It takes quite a lot of time to repeat all the wrong doings of Epic and it’s CEO Tim.
Thus, I can only relay to the collected information of bad old Reddit, if you want to (I’m intentionally not linking, you can search it up easily). r/fuckepic has a lot of collected information on their side page.
In short, biggest issue for me exclusivity contracts with games advertised on Steam, then as a bait and switch removed from the store page and their physical copies getting a sticker on top of the Steam logo, so a last minute deal, for Metro Exodus. And then they continued their exclusivity hunt for games, they didn’t even helped to develop. Nothing against self-made or published games to be limited time exclusive in my perspective, but not second hand bought (out).
The other about their CEO, r/timcritizisestim He’s… a douche. Using kids with the free games to bait them to his store, using them against Apple’s store rules like a little army… he is a bad person with too much money and luck to have build the Epic engine with Fortnite…