Valve isn't likely to make SteamOS the kind of platform that facilitates intrusive* anti-cheat** or which is locked down in a way to prevent cheating at the client side. This means that a number of competitive multiplayer games will never run on it. I think in this regard, consoles still have an advantage*** if you're into those kinds of games.

* I don't care what the intention is, they are _objectively_ intrusive.

** Last time I argued this, someone seemed to assume that I was claiming that writing Linux kernel drivers is harder than Windows kernel drivers. I am not arguing that, you need some kind of trusted party enforcing signed kernel drivers and a signed kernel in order to make KLA sufficiently hard to bypass.

*** In terms of the average Joe just wanting their game to run rather than having to think about the ethical implications of buying hardware you don't actually own or running an OS which gives control of your hardware to various corporations (but not you).