There's so much to talk about when it comes to the early MMORPG days, the early days were really something special. People forget just how niche the scene was and how small the player base was for the very first MMORPGs, FFXI has already been mentioned but the tl;dr is that before WoW blew the scene up it was incredibly small even by the standards of the time. It sounds silly but back in the day there were plenty of people that thought the internet was more of a fad. Something for hobbyists that had too much time on their hands and not enough time spent in the sunlight.
I think really what captures the spirit of the time is not just the novelty of being able to interact with other people but the atittudes and the demeanour of the people playing MMORPGs. You're right when you say people used to live them, for a lot of nerds back in the day it was basically an alter ego and while it might be true today the people that played back then were so, so, so, different. These days it's not quite the same, the basement dwelling D&D nerd that's also a programmer has been replaced with a fairly normal, average person. It's hard to describe but the old players were incredibly eccentric and passionate.
People often don't understand that just having access to the internet let alone a home computer back then was a real luxury that the majority of normal people simply didn't have. It hadn't quite become adopted by the 'mainstream'. I'm not saying video games (and interactive media) weren't well on their way but there was a magnitude of difference. Normal people don't really interact with the medium the same way these people ever did and still don't. The closest you might find to that atmosphere nowadays is a Neverwinter Nights RP server or some kind of niche RP scene that's running a grognard game.
My first experience really was just how incredibly kind but also how incredibly high the community standards were. Back then, MMORPGs were quite limited and frankly games like Everquest, Ultima Online, FFXI expected you to suffer. They didn't have quest markers, or any real guidance. Information came from word of mouth. There was no data mining. Online help was limited to sites like gamefaqs and guides only came out much later on. There wasn't a thousand different articles written on day one by hack journalists regurgitating the meta. You had to learn from someone else and that was always other players!
I made a character called Momoro. A taru taru White Mage. And I had no idea what to do, the intro sequence which roughly points you in the direction you're meant to explore didn't play properly for me because my PC was a potato. I spent well over an hour shouting out in broken english trying to find someone to help before a hume Paladin called Maxwell and his Elvaan wife Aliashara found me outside the auction house. These were some of the few max level French speaking players. And frankly Western. Back then you couldn't pick a server, you were assigned one. And I got placed on one with a very heavy Japanese population with a very light but active English speaking one.
We spent about two hours just going over how to play the game. How to use abilities, how to target mobs, how to attack things, what this thing called auto-translate was that I wasn't using, a very good system that lets you speak phrases to anyone and they babied me. They gave me (in game currency) gil. They explained to me there was no handholding from the NPCs, that I needed to be nice and ask players for help if I wanted to get anywhere. And work together as a team! I couldn't afford to be rude because my reputation meant everything. When they eventually left, I got my 'quest', my signet and went to grinding.
Periodically, I remember Aliashara and Maxwell checking in on me in tells to see how my progress was going. Encouraging me, and promising that once I got to level 10 I could join their Linkshell (guild) as a social player. I did join, and even today, we're still talking. They're genuinely, sincerely, some of the closest friends I have despite a near twenty year age gap. We're family. The entire linkshell is eccentric, friendly, characters that wouldn't feel out of place from a manga. And it makes me sad that style of community no longer exists.
I know it's a trivial, boring rant, I guess my point is that you simply don't get interaction like that any more in MMORPGs. It's not just because MMORPGs are made differently - FFXI definitely demanded a strong community by the very design of the game, people were generally friendlier back then and MMORPGs (as well as the internet) were obviously more niche - but modern MMORPG players are so incredibly jaded, bratty and spoilt. So indifferent. So selfish. So entitled. They excel at apathy. Me, me, me, that's all they care about and I wouldn't mind but this meant to be a community orientated style of game, or at least it was.
They treat other players like a nuisance at best. Like they're ghosts from Dark Souls. An inconvenience they try to avoid because not only do they no longer have to rely on other players to accomplish their goals (and the novelty of socializing online is completely dead) but everything is trivial. It's an atomized community where the individual has no value. It's all so dehumanizing, and all for the sake of convenience for an audience that doesn't even seem to really want to play an MMORPG or even treat them like a chat room. And if they do, it's not in game chat it's on discord. In secluded bubbles, away from other players, in an echo chamber.
.. I'm not sure what I was really trying to convey. Just frustratrion I suppose, in persuit of money MMORPGs have forgotten what they were meant to be about. The end result is that all those unique player interactions and experiences have been streamlined out of them, so players can rush to the end game. Just so they can log in to auto queue in to a raid, with people they'll never see again or even speak too, or log in for 30 mins to complete a daily goal. And I don't begrudge people for valuing their time, I just wish the modern MMORPG formula didn't cater to people that have no interest in playing one.