hot take re: Linux ports
I think it's important to keep in mind that just because something is in Gamemaker or Unity doesn't mean making a Linux port is as simple as pressing a button that says "port to Linux". It's a bunch of work and then you have to support the game on all the different distros and weird configurations, it's a commitment.
Not saying it wouldn't be nice if all games were available for Linux but it's not free or easy, especially for small studios