There's a little more to it than "just a launcher." My Steam account dates back to the release of Half-Life 2. Loads of games, thousands of dollars spent, and a service that's been reliable for over 20 years. Why would I use a different service? I'm not unique, everyone else using Steam is in the same boat, just with less time invested.

They've undoubtedly locked us all in, but they've shown themselves to be trustworthy and reliable.