You don’t need SteamOS to game on Linux. I’ve heard good things about Bazzite, and there other Linux distros that focus on gaming.

SteamOS will most likely be deployed on other handheld PCs, not desktop PCs. The handheld PCs that came out in response to the deck’s release (or before) usually run Windows.

Android is not bad because Android itself is bad (well… it kinda is but let’s just assume it isn’t), but because the phone manufacturers lock down their phones’ hardware. They do this to force you into their ecosystem. With SteamOS, you already have an ecosystem, which is Steam. There is (at least for now) a clear distinction between Hardware manufacturer and software provider.

For now at least Androidization is nothing you should worry about. Maybe in 10, 20 years. edit: and even then it’s never going to be as bad as with the smartphones