From the perspective of allowing more and more games to exist and do well on the market Valve is doing amazing. This talk goes over some of it https://www.gdcvault.com/play/1025672/2014-vs-2018-The-Shape but essentially there are 1000+ games right now on Steam with over 100 concurrent users. One of my games got about 80 concurrent users at its peak and it made a small but fair amount of money (especially for someone's first game), so it's easy to see how 1000+ games with that many players means a lot of financial success to a lot of people, way more than ever happened before for game developers.

One of the things that amazes me about Valve and the way they run Steam is that I released my game, had thousands of people buy it, pushed updates, communicated with users, got paid, and I had to speak with 0 human beings at Valve. It all just happened in a very predictable, clear and highly automated way. This lack of friction is absolutely amazing for developers, especially people like me who live in a third world country and would otherwise have more difficulty going through these processes for any number of reasons. So IMO they're doing something extremely valuable which is properly acting as a platform so that other game developers can succeed and make more and better games for everyone.