Yeah, Steam is a monopoly, but 1) they’ve been a monopoly since forever and there hasn’t been a Comcast-ish disaster, and 2) more competition doesn’t seem to actually benefit us here but could potentially make things a lot worse.
In principle, Steam is a Sword Of Damocles just like any other Monopoly. In practice, the alternatives are EA and Epic, no thank you (I know itch.io is a good competitor, but they don’t have any pull on AAA publishers so I don’t expect them to take the market if Steam implodes).
Also, Valve is innovating in ways that nobody else seems willing to - not just their Linux ports (represent!), but also their attempts on HTPC gaming (which was unnecessarily a huge pain in the ass on PC, for no good reason) and their steam controller. And their portable PC gaming with the Steam deck (which to be fair GPD probably did first).
All in all, I’m happy to pay the Steam tax for what they’re doing. I have no illusions that Epic Games Store would provide serious competition in terms of the goodies I want, because they already aren’t, and they’re still in their sweetheart phase.
They disrupted the status quo back in 2003 (2001?), then in 2009 they were doing Linux ports, then in ~2015 they were doing HTPC stuff (and also funding Linux graphic driver dev the entire time, Linux gaming in its current state would not exist without Valve), there was their Steam Machine experiment somewhere in there (it flopped but that doesn’t make it cost any less), then they were doing Steam Deck stuff. They’re still paying Linux graphic devs BTW.