It goes down after a certain amount of sales. 25% after 10 mil and 20% after 50.
It says a lot about how large valves market share is that they can take such a large cut and publishers will still sell there. Plenty have tried to release alternative clients without mixed success
It's the userbase. Steam works well enough, hasn't changed really at all in years (a feature in and of itself), and has mostly everything a user would ever want or need.
Why then install an alternative client?
Source: I tried to compete with steam once. Tech was better. Nobody cared.
I wouldn't even say Steam works well. The UI is laggy and clunky, the mobile app is a joke (literally worse than the web version). But it's good enough, it beats learning something new, especially since all game launchers seem to have some flashy custom UI instead of standard widgets.
I think Steam works very well. I heavily use in-homestreaming and big picture mode on my shield and it offers a nice experience that I've yet to see emulated elsewhere. I usually have a browse in the store and watch trailers on the TV before launching my game.
Remote Play is fun on games that support it.
And it runs on osx, linux and windows.
And then theres Broadcasting, chat. Its a heavily featured launcher, and offers way more than some of the alternatives out there.
It says a lot about how large valves market share is that they can take such a large cut and publishers will still sell there. Plenty have tried to release alternative clients without mixed success