Valve won't stay that way forever—the company is not immune to the pressures of capitalism
I'm glad that the author recognized the actual root cause of their argument, which is that Capitalism is bad and ruins everything, but why blame Steam for essentially just existing in a Capitalist world? They didn't choose that, and they're certainly doing a hell of a lot more than almost any other company their size that I can think of to resist shitty Capitalist practices.
It really feels like this author is just saying, "they're resisting anti-consumer enshittification practices now, so the only place to go is down, ergo 'timebomb'!".
"Every person who isn't a murderer is just a murder away from becoming a murderer. Timebomb!"