* Just works
* It's simple
* Cloud saves all of my games (with a few exceptions when the game developer doesn't enable it for whatever reason, this has only been for a few games so I'm not sure why)
* Family sharing - this is HUGE for me. I can't re-buy every single game for my kids, so the fact that they can just play a game I purchased on their own account when I'm not online is an insane life saver.
* Steam sales- yeah maybe they aren't quite as good as they used to be.. but still, before steam started doing sales I was buying $60 games. Now I generally just wait 6 months and never pay more than $20 for a game, usually even less
* You could argue the indie game world would basically not exist without them. Indie games are basically all I even play on steam- and I buy a lot of games
I could keep going on.. but honestly Steam just works. It's not the prettiest, but that's fine. Steam is like a web 1.0 site that does everything you want it to, and anything since then has been web 2.0 pieces of garbage that try to do all this fancy stuff but are unusable or annoying as hell.
Epic Games Launcher is garbage. Microsoft store is garbage.
So yeah it's weird, I am 100% OK with Valve getting the premium whereas I think it's sickening that apple/android do what they do. They are basically a walled garden. Steam is not, there are infinite ways to distribute a PC game.
Probably the oldest tech company that can really say "we are not evil" and instead are actually helping both the consumer and developers.