alt Hacker News> with no meaningful alternative
Steam (which I'm guessing you're talking about) is nowhere close of being a monopoly. There are loads of alternatives out there, in wide use by people already. World of Warcraft, League of Legends, Minecraft, Roblox and more are all examples of big time successful games that never been available on Steam.
I would even go further, and say that this logic applies not just for massive games from massive publishers, but platforms like GoG works well as an alternative for indies.