Unity announce expanded support for Steam, Native Linux, Steam Deck and Steam Machine
(www.gamingonlinux.com)
I would rather see Video games (even Proprietary) be built with more open source engines.
Or custom engines.
Middleware like FMOD is okay.
Havok(only in Source its okay)
Bink(only if its the first version of Bink Video since FFMPEG can easily decode it)