I think a big chunk of it is; Normal people cannot cooperate with others.

Like, Vermintide, Darktide? Pretty niche games where cooperation is both necessary and enforced by special disabler and assassin enemies.

HD2, success also required cooperation, but it reached a massive audience and most of those people... just... don't... communicate. They don't ping, they don't use chat, they don't use voice. They don't even passively stick together. I worked out, it actually makes things exponentially worse when you have players that don't cooperate, because they trigger every patrol and spawn, they don't cover or protect each other, the players aren't making use of all their strats together. If you're all together you're rarely ever not going to have some gigantic bomb ready to go. BUt if it's four people running off alone they're gonna get overwhelmed even by minor threats. And since they don't know how to cooperate they don't know they have to cooperate, so when they get absolutely ruined by something that would be trivial for a squad working together they can only think that the game is being mean and punishing them.

A