Steam is usually well run to the point where it’s merely a pain in the ass. It also provides some benefits to the user (i.e., I can re-download games), but that has nothing to do with DRM (i.e., I can re-download GOG games).
My concern with Steam is that if the quality of their service starts to go down hill then it could be a real impediment to enjoying the games I’ve already purchased. For instance, if they stolen steam accounts, arbitrary deletion of games from accounts, server downtime, long-term denial of service attacks and any number of other scenarios become a problem, I’m not sure they’d handle it well. Their customer service is already terrible.
And of course they could just go out of business.