On the subject of game development at Valve, there's a lot of things that have been worked on but never turned into an actual release. There were 5 cancelled Half-Lifes between Episode 2 and Alyx (Including Half Life 3), Left 4 Dead 3, F-Stop, "RPG". A.R.T.I, SimTrek and probably a few more.
That sometimes over-cancelling willingness I think is also part of what makes the end result great-TF2 took 9 years and several versions similarly to Alyx, but I think both were worth the wait.
Steam's only other potential competitor was GOG, and it seems those two have had a fairly friendly relationship over the years. Remember that Valve gives away Steam keys to developers and resellers at very little cost, and that there are thriving third-party markets because of that.
You could argue that they have been stagnant in terms of game development, but everyone knows that isn't exactly true since Alyx was released. I don't really know what state VR was in before its release but from this outsider's perspective it seems to have raised the bar considerably.
Save for GOG, the DRM war is effectively lost, and so I'd rather be living under Gaben's benevolent dictatorship than some of the other more corporate-minded masters.