Man, anybody whining here hasn't tried to sell a video game.
Any studio that joined in this sweep of Epic Store games got a few things: that 12% bonus on revenue, plus a giant ad on The Game Awards for their games, plus first dibs on the barren Epic Store front page, PLUS a potential discount on their UE4 license.
And in exchange, they tell their PC players, "install one more game launcher." Not perfect, but that's reallllly low friction for a game dev to face in terms of getting more bang for their buck. (They're not selling your play data to a third-party tracking service, or pinning you to Win10's UWP, or other actually bad use cases.)
If you want to pick a bone with fragmentation because Linux and Steam work hand-in-hand, great, talk about Linux. Everything else being said here sounds pretty off-base.