Go to Steam Forums for a game that doesn’t support Linux
Post a new thread, politely asking about the possibility of native Linux support
A Windows fanboy appears to tell you that you are wrong
Warning: Since the introduction of the Steam Deck, it’s a bit harder to conjure up a Windows fanboy on the Steam forums, so you might have to try on a couple of game forums to conjure up your Windows fanboy.
Your can conjure them up quite easily.