I've tried for like 20 minutes to put exactly into words what I hate about the game without making it too long or unfair

I think to keep it simple its basically because the kids who play are annoying (70% of the players or so), there are a good amount of toxic 20 something year old tryhards (20% or so) who are just really arrogant and talk about the game and how to play like it's the most intense test of intellect or reflexes that you could ever find and in general look down on new players or players of other multiplayer shooters (they also turned what could have been a great unique shooter with some cool building mechanics into basically a competition about who can build the fastest), and then there are just the new/ casual players like most people who hate on the game who get harassed by the kids and tryhards (not very different than any other game though)