It's getting pretty easy to ditch Windows these days. Microsoft got too greedy and desperate, and actually using the damn platform they built is getting harder and harder, especially if you don't want the nagging and annoyances that come from them trying to turn your computer into their subscription revenue stream. My impression is that Valve is aware of the problem, and wants to make sure that their store works regardless of which operating system you prefer.

You'll be just fine. So long as they fix the issues with anticheat software at some point. Gaming on linux is great these days in most cases though.