PC's are intentionally gimped to prevent trivial copyright infringement.

Netflix forces you to use Edge on Windows or Safari on Firefox to stream in 4k because they integrate with the OS's DRM.

HBO Max doesn't allow 4k at all on PC's but I think will at least do 1080p if you use an approved browser.

I don't think Hulu will stream anything higher than 720p regardless of which browser you use. Disney+ is the same.

Good luck getting anything over 720p running Linux and Firefox.