It's especially a case of one thing not being like the others since all the examples are qualified by the phrase "the surplus is handed to shareholders". But every other example is a public company, with a vast array of public shareholders. Valve is private and, as far as I know, has >50% ownership from one person.

I feel like the argument as a whole for enshittification would be more interesting if it actually allowed for nuance rather than the rabble-rousing "all platforms are evil!" cry that it's becoming.