Probably the most famous example is when their store app was caught copying Steam files, collecting friends play history, and scanning running processes.
https://old.reddit.com/r/fuckepic/comments/wakewr/epic_games_spyware_vs_steam_vs_as_comparision_ea/
https://www.pcgamesn.com/epic-launcher-spyware
Separately, Epic Online Services (which is embedded into many games from the Epic store and some from other stores) collects more information than many people are comfortable with.
And then there's the fact that Tencent owns a sizeable chunk of Epic.
Some folks don't mind these things, but they're not okay with me, so I don't allow software from Epic to run on my systems.
Do the arena wall features look like a face to anyone else?