Sure, competition is good but, unless they go the scummy anti-consumer way, which is purchasing exclusives like Discord did, failing miserably, and limiting people power and options in doing so, I don't see how they could even remotely bother Steam.
Valve managed to make people accept the idea of DRMs by giving in return a whole range of tools and instruments, features, social aspects and the freedom to purchase and sell a game wherever you please (even directly from the developer). On the other side, we have GOG, that pushed their service on the ideology that games should never be behind a DRM. Users of both platforms have huge libraries on both sites and enjoy the service they offer. In the light of that, how do you expect people to switch to a third different platform that will, at best, offer the same features of the two?
I know I won't. If they force me to have my PC games scattered around a gazillion different clients, I'd just go drm-free when possible.