well, this is my question.
I move more and more things to GoG.
Is there a reason why most games are released on Steam besides the sheer market dominance Steam has?

I really buy most games these days on GoG, not Steam.
Thanks

This is kind of an odd question to post on a website that's neither Steam or GoG. Are you asking why game platforms outside of Steam aren't as popular? Or just GoG specifically? If you're asking about GoG specifically you could post that question on the GoG website and you'd likely get more relevant answers