Find me a source confirming that they actually studied Steam’s position in their market.
I found a super recent source that does not list Valve as a monopolist. Maybe you should go and find a credible source other than “Trust me, bro” that Steam is a monopoly.
They have specific criterias, including financial and user ones, and Steam doesn’t meet them… oopsy!
So Steam does not rake in so much money to hog the market and also does not have enough users to hog the customer base. If anything is an oopsy, it’s you accidentally admitting that Steam is not a monopoly. Good we cleared that up!