i like a few multiplayer shooters, fortnite being one of them. i also exclusively use gnu/linux on my machines, so i got around this issue of games like fortnite/battlefield/etc issue a long time ago by simply doing what i've always done for years, playing these on xbox. i even 'stream' these games to my linux machine from my xbox if i want to play them from the computer with the xbox controller, and can join and create xbox live parties through the xbox web interface.

i only do this for those couple of games i play with friends that won't support linux because of the aforementioned rootkit it wants to run on windows machines. console for those games, and all my other games run happily either through steam+proton or natively on linux, and there are a fair few FOSS games with amazing multiplayer. i love luanti, xonotic, openarena, veloren, etc, and play them frequently with some friends. :)