Dusk: Unpopular opinion: I'd rather pay Valve 30% and put up with their de facto monopoly than help Epic work towards their own (very obviously desired) monopoly
But Steam doesn’t have a monopoly. There’s Epic and GOG and whatever Origin’s called now and probably others. They’re all free to exist, Valve doesn’t do anything to stifle competition, and even lets other companies sell games that start their launcher from Steam.
The only thing you have to lose by using a different system is that it’s probably not as good.
All they’ve done is produce a really fucking exemplary product and it’s become really popular because it’s honestly just good. The second it stops being good or Valve stop being awesome there’s plenty of alternative ways to buy games that I’m sure will be there to replace it.
The position makes a monopoly so I would say they are but they remain the good guys because they don't engage in anti-competitive practices, you can have a monopoly wven if you don't abuse it.
Monopolies aren't based on the mere existence of competition. It's based on power and market share. Eg, Chrome has a monopoly. Firefox, Safari, and a few niche browsers exist. But Chrome is the utter vast majority of the market and has pretty much all the power on dictating web standards as a result.
Microsoft had competitors when they got sued for their IE + Windows monopoly. But they had an utterly massive amount of the market share and used that to push their own browser.