Having only played the demo for Cosmic Invasion, it seems to have the same problem as most "revival" beat-'em-ups of the past few years, where "depth" is replaced with "content." Studios have been scratching their heads over how to market beat-'em-ups to the modern consumer who demands "endless" content, and have arrived at two solutions: bog the game down with RPG mechanics and grinding, or make it into a "roguelike." Neither solution is satisfactory because it basically kneecaps the gameplay of a beat-'em-up in favor of "number go up" systems or massively unbalanced "roguelite" upgrades which make the game piss-easy or super-hard depending on build (or lack thereof).
I really have to wonder who these games are for, other than nostalgists. Modern gamers are not going to play through a boomer beat-'em-up just because it has an upgrade system, and hardcore beat-'em-up fans (however many of them are left) are not going to walk away satisfied.
The most obvious concession to this lazy non-design is imo the inclusion of "dodge" and "block" systems (which aren't even distributed equally to all characters!), basically telling you that you have to "wait your turn" before you can respond to the enemy. And they double down on this conceit by making bosses damage sponges with lengthy periods of invincibility in-between AoE attacks you're supposed to just run away from. This goes completely against beat-'em-up gameplay which is about position, crowd control, resource management, and proactive play. This is the Dark Souls-ification of arcade games. It has more in common with an FFXIV raid than with Final Fight.
However I will give them that the sprite art and animations are gorgeous; that alone, combined with 90s Marvel nostalgia (which I am not immune to), is probably enough for most people, most of the time.