Now on a desktop PC sure I believe these fingerprints are highly descriptive. And in android land they probably work okay because of the diversity of products and configurations. But iPhones resist fingerprinting just because they all give the same answers.
The web provides:
time zone language and locale (accept-language header too) iOS version screen size and pixel ratio text size dark/light mode reduced motion ad blocker extensions for safari
An app provides (without additional permissions):
IDFA advertising ID (unique and cross app) IDFV (vendor ID) AdAttributionKit (which apple does obscure somewhat) Battery level, charging state, volume, headphones Various appearance settings again (font, dark/light, reduced motion)
Just slightly more permission granted via prompt can get you:
System boot time and uptime Disk space Keyboard languages and extensions File timestamps
Then additional individual permissions (which people agree to all the time for specific use cases)... at this level they can single you out easily: location contacts bluetooth motion sensors
To Apple's credit they're trying to make fingerprinting more difficult and attempt to ban it entirely, but it's not at all impossible.