Back on Reddit, there were even complaints that EA's anticheat was conflicting with Riot's anticheat. Yep, now you potentially need two different installations of Windows to run each of your games. At this point, you would need to buy several SSDs and a SSD extension (or an external USB reader, since USB speeds nowadays are relatively fast enough to afford running those games from an external drive), then install each game (and operative system) in a different one, and swap between them before booting, just like a cartridge. Same would go, of course, for your actual main GNU/Linux drive that contains your actual personal data - that way, the anticheat can't even see your personal information, as it'd physically unplugged from your computer. And since Windows checks the license per motherboard, not per drive, you should be able to recycle the activation key between your Valorant "cartridge" and your Battlefield "cartridge". At this point, paying for a dedicated game console and the online pass starts becoming attractive...
...That, or just boycott multiplayer games altogether. If your group of friends doesn't mind, of course.
It's not that I dislike buying games from another store (I have quite a few from GOG and Itch), what I'm wary about is the loader - especially knowing that Epic is too buddy-buddy with Tencent and both are known to siphon unnecessary amounts of user data.