How did Valve avoid Enshittification?

The model where you pay $X to get a game and Valve collects $aX where 0 < a < 1 is a user-friendly model in the long term.

Contrast to the awful "free-to-play" mobile game model and Xbox's GAME PASS model that is certain to go to hell the same way Cable TV went to hell. (Parents who hate video games and would think their kids will quit playing if the games are boring will rejoice but their kids will be grown up by the time it gets that bad.)

My argument is probably insufficient because I think the Apple App Store and Play Stores are really crammed with crap and I'm quite annoyed that the App Store hides the search box because they'd rather spam me with ads for games and apps I don't want.

Boy I feel like a voice in the wilderness railing against GAME PASS because I often pay anywhere from 10% to 5 times the monthly sub to get a game and defenders of GAME PASS will point out "Look, there are even some of those weeaboo games that you like on GAME PASS".

There are a lot of possible reasons, but I think most of them boil down to Valve being privately owned. There isn't an enormous table of shareholders begging for constant growth and return, so Valve was given time to scale naturally and colloquially "pick up [sic]Steam".

That’s a loaded question. I don’t think Valve avoided enshittification at all.

Valve was an industry leader in integrating gambling into mainstream video games. They’ve also integrated pay-to-win microtransactions and exploitative battle passes into recent titles.