They patched CS:GO away, a game I paid retail price for, with "Counter-Strike 2" and overnight dropped support for my platform (MacOS).

Sony has never stolen a game from me, unlike Valve. The closest incident was that movie thing, which was more a failure on their part to negotiate perpetual licensing with the rightsholder.

Valve pivoting away from MacOS is a consequence of choices Apple has made for their platform, many of which made it a more hostile place for Steam to exist. This is baked into the long standing Apple model of software distribution, where API and architectural changes inevitably obsolete software with Apple usually providing only a limited time window for cross compatibility.

You can still play your purchases on an operating system that isn't actively fighting against you running them.

CS:GO is still accessible via the beta feature. Not sure if you can still play it on MacOS. I agree that that's the wrong way to do it, but at least you still have access to it in theory.