Last year, they all came crawlin' back to Steam, and this year was another strong one for Valve.
From the opinion piece:
Last year, I pointed out how many big publishers came crawlin' back to Steam after trying their own things: EA, Activision, Microsoft. This year, for the first time ever, two Blizzard games released on Steam: Overwatch and Diablo 4.
Valve has objectively done far more good in the gaming space than any other company so I would say yes, their achievements are worth celebrating even if it is monopolistic. They've proven to be trustworthy for the time being, unlike other companies.
It's not a monopoly in the way that valve has does bad things to keep it that way, just that every other try has so far failed. Nothing has been close to as good as steam, and probably never will. GOG is good but they're not directly competing in the same way.