It's called a network effect. At some point, you use it because you use it. And without any killer feature, you have no reason to move. It's not "wrong", but it explains why "just do better than Steam" does not work.
No, I am sadly human. Heck, these days I'm sloppier with my typing specifically to avoid such accusations.
You asked why and I answered with the real reason. It's not that deep. People don't leave because people don't leave. If that's not a satisfying answer, I agree. But reality can be irrational.
Did you use an LLM to generate this? Don't do that.