I have some thoughts and disagreements on your assessments in this post, but I'm still mulling it over before commenting further. But this specific thing is worth pointing out: I'm not sure how technically savvy or security conscious you personally are, but about this specific thing you should consider this more of a "best-effort" on apple's part rather than some protection that you have (because you're using apple products,) that is being adhered to in a real way.
I can get into the weeds on this but honestly it'll probably make most folks' eyes glaze over; but this page has some worthwhile points about apple's "ask app not to track" specifically:
More generally, even if apple were to block the app from tracking via your phone's internals (which apple can and do block these if you ask,) operational security around how you use your phone and any particular app means that you are still very, very much trackable (and tracked).
A lot of that is true, but apple is getting better and are doing more than most companies.
They have introduced features that now help you catch the apps in the act of trying to track certain things they have control over with permissions. Such as reading the phones clipboard, taking a stealth screenshot or screen recording and accessing microphone and GPS. You get badgered with prompts telling you so and so app is requesting access to the following and you have to either grant or deny that request.
A lot of companies cried foul play when Apple introduced this.
But yes, a lot of other tracking can skirt by. Hence my use of VPN's as well as ad blockers.
I have my personal data pretty locked down, but as a result, there are a few apps and many websites that will not allow me access unless I disabled my ad blocker and VPN. "Because that's who they make their money", and they love to rub it in your face like you are unethical and stealing their service. And when I see this happening I either delete the app, or bounce from that website and never return.
And that right there is what I think we need to truly address. Being able to opt out without having to forfeit access to a service.