Right, Apple doesn't have an ad-revenue & tracking empire to protect, and should Safari adopt PPA, the discussion changes. It would no longer be the API used merely by Firefox with its (estimated) 2.7% user base trying to gain any traction, it could be Chrome holding back the tech used by a cumulative (estimated) 20% of web users. That's a very different conversation.

Also, despite advertisers and big tech's best efforts, the chance remains that legislation is passed somewhere imposing stricter privacy protections on the web. Again, should that happen, PPA might be well positioned as an alternative to past methods of measuring ad effectiveness that advertisers wouldn't necessarily like... but any alternative that works could make them less resistant to such an important change.

All hypothetical, of course, but if you never consider future possibilities, what are you even aiming for?