I don't understand how the Apple that introduced their Content Blocker APIs would choose to invest into this API to kneecap their own content blockers?
They wouldn't have to. Unless you use an iDevice you're not using an Apple made browser. (The content blocker API is WebKit so it's used across multiple browsers)
As for revenue from Apple users, they already want to have control over that and would be more than happy if Google and co voluntarily stopped serving their users so they can make ad money off of them on their own terms.
