Personally, I feel that there are different genres of games where different arguments can be made, from fighting games to RPG games. But I personally am fine with non-optimization being allowed while still having "optimized" choices due to the playstyle for said choices being different. I feel that Pokemon games are the best way to display this due to the disparity and contrast between the "casual" and "competitive" sides of the games, as both sides are very popular and well-known within gaming circles.
For example, in single player Pokemon, you can choose different Pokemon and still come out on top, as long as you strategize correctly using the best moves, and if you are a singular typing, you still cripple yourself as a non-optimized choice, making the game much harder than if you used multiple types. Despite this, you can still win, and this is not the recommended or implied to be recommended choice by the developers, as your rival counterparts who you fight throughout the game often have Pokemon with differing types. In other words, strategy is a key part of the game, and not making your choices on par with said strategies in game in terms of either moves or Pokemon may make things more difficult. If you are weak in one part of the strategy, such as with typings, then you need to improve your other parts of strategy such as with moves.
On the other hand, with The Pokemon metagame, things are very different, as there are different Pokemon in different tiers, and Pokemon themselves need to be optimized to survive and thrive within the different tiers. There are EVS and IVS, ensuring that every Pokemon is different and those stat values themselves are viewed as the bare minimum as to what needs to be optimized in order to play competitively. In addition, despite optimization, there are some Pokemon which are destined to remain in lower tiers no matter what you do, having the tier system of fighting games while also having other factors in preparation which are often ignored in the casual single-player system, such as EVS and IVS. If you apply these strategies to the single-player side however, then the game often becomes steamrolled or too easy.
Pokemon is a very well-known franchise, but it still manages to be popular on both fronts due to its disparity, so its likely that the average person would like to engage with mechanics that allow for enough adaptation to have a general playstyle, while not being uber-specialized in either needing optimization, nor being adaptable enough to have every encounter be easy for all playstyles. I feel like this question was answered with "archetypes" in even older tabletop games and wargames, such as classes in D&D, as they allow for multiple different roles with their own characteristics while still allowing for strategy to fit the situation be needed rather than being infinitely adaptable, while also having said roles be obvious enough (at least to those familiar with gaming conventions) that you can tell that a berserker and a monk might be counterparts just like a druid and a mage can be counterparts, being broadly "physical" and "magical" classes respectively.
RageBurner mentioned Monster Hunter, and it made me realize how good Monster Hunter is as a game, as every weapon, while not even being equal against every monster, has enough of a niche to be able to conquer every monster solo or work well together in a group. While some games may have some weapons be better than others, Capcom puts time into balancing each weapon to make choices feel fair for players and to allow them to match the playstyle, even if some may struggle more against different monsters. Monster Hunter also heavily requires the usage of items, allowing for simultaneously more customization on one end, while also giving the developers another avenue and more leeway to measure difficulty, such as with certain ranged weapons needing ammo, allowing for certain weapons or equipment within the same weapon class to need, want, or like certain items more, or simply allowing for all members of a hunting party to be valuable in item usage.
Megaten games are also pretty interesting in that department due to their fusing system, creating "party members" of a sort that are usually associated with a certain element or a task, such as consistently fusing personas or demons with electric skills to create an "electric" party member, while still transforming into different creatures with different broader strengths and weaknesses, such as how well they deal with a certain element. Demon customization is usually the main meat of the game, so non-fusable party members are usually just pretty good all around or in certain aspects to showcase their usefulness and to give you a good grasp on how to use them. Persona games have more examples of human party members, so I'll elaborate more about them.
The non-protagonist party members of modern Persona games, are often associated with one element while also having varying physical prowess, sometimes being good at physical attacks and having many physical skills as a result while still having elemental attacks they do poorly in, and sometimes being good at their element and being poor at physical attacks and lacking physical skills as a result. Most find a balance between the two extremes, but most playing the series choose to have the elemental skills be focused on for the "mage" party members in order to strike weaknesses. The non-customizability of the Persona party members gives a broad archetype which you can imitate with your fusable personas, such as the physical party member to use when you believe physical attacks will be valuable and the physical persona line you have due to thinking you need a dedicated physical user. The party members usually also have better stats and skills for the level compared to your fused personas, allowing them to stand out more.
This simeltaneously makes the non-protagonist party members useful to take along in nearly all cases, due to physical stats being balanced to potentially grant extra turns against boss type enemies if a critical hit occurs and be more effective against enemies with no weaknesses as a result, and elemental enemies granting extra turns if you hit them with their weakness, with the exclusive elemental affinity of different party members allowing all of them to at least be usable by playing into the "one more" gameplay system. as well as allowing both the companion party members to stand out with their specialization and the heroes to stand out with their adaptability, and makes non-protagonist party members function as a broader "archetype" to imitate when fusing personas. In addition, the party members which have poor elemental attacks but good physical attacks reward creating personas having good elemental capabilities consisting of the elements said party members lack, allowing you to apply knowledge of what the other party members are capable of, and allowing for you to showcase usage of the knowledge given to the player through the abilities of the other party members, and both imitating and adapting them with your own personas, such as with a healing persona fusion line created to adapt if more healing is needed and if the healer is gone, or a buffing persona line granting buffs and debuffs that are usually split across party members.
Personally, I am fine with and even like optimization, as I view it as part of the game as fun to play around as part of strategy, though I prefer games with infinite opportunities to respec, similar to the Final Fantasy games with job systems. My most favored type of game would be similar to Monster Hunter, with not all options being equally good in all situations, but being fairly balanced overall as well as standing out from one another. I usually use the first of most types of units in games due to them usually being the most plot relevant and getting them early making them stand out as a result, such as Caeda and Merric due to Caeda being able to recruit multiple characters or Merric being able to use Excalibur and being a good emergency mage respectively. Another example would be having Ryu, Nina, and Bleu within my party in Breath of Fire games, with the last party member being whoever else is important within the game, such as a fully fused Karn or Bow. I use fire type starters usually in Pokemon games due to that element alongside electricity being associated with "heroic main protagonist" characters, and I usually use main character type characters in fighting games, which usually end up being shotoclones. I use the charge blade in Monster Hunter due to its adaptability in combat as well as being able to become impact or elemental based, allowing me to tailor the weapon to the situation as equipment. I try to make my choices fit the character when optimizing, an example from FF5 being Bartz being a Mystic Knight, while Lenna becomes a Summoner.
