The weirdest thing is that steam doesn’t have a natural or self reinforcing monopoly. It wouldn’t take much for another company to copy their business model, and provide a competitor. In practice, however, they all fall flat on their faces.
Steam’s model is to give up short term gain for a smaller long term gain. Over time, this has snowballed into what we see now. Gabe is happy to get ever richer from his golden goose laying away. The competitors get started, then try and gut the goose for a quick buck.
It takes some practice to beautify it. You’ll also spend more time doing that than the whole time taken to build the core.