> Either you add a compatibility hack to the OS or you drop support for that app.

It isn't really a binary choice like this in real life. This really depends on the specifics of what the breakage is. The best way is to not break the caller's expectation to begin with.

Anyway, my point is that patching on the vendor side is way more common than it would be in the days before internet updates were common.

It's still common with modern operating systems. I think the bias may just be from historical blog posts talking about old events than newer ones. The developers adding these are under NDA so they aren't going to be sharing with the world what they are doing.

You are right that it's not a binary choice, they are others like maintaining tech debt forever or paying out of pocket to upgrade people's apps. But it's common for those to not be viable options and operating systems need to keep evolving forward.