Apple provides telemetry services that strips the IP before providing it to the app owners. Routing like this requires trust (just as a VPN does), but it's feasible.
Why is it relevant whether they provide it to app owners directly? The issue people have is the information is logged now and abused later, in whatever form.
If the app owner can't obtain PII, I don't believe the app owner is spying.
Is Apple spying?
> Routing like this requires trust
It depends on if you trust them, and their privacy policy. If they're functioning as a PII stripping proxy, as they claim, then I would claim no, to the extent of what's technically possible. I would also claim that a trustworthy VPN is not spying on you. YOMV.