fingerprints pick up on all sorts of things that make you different enough combined with another signal, 33 bits can be enough to single you out from anyone else on the planet... iOS can be 10-15, and given a residential IP that's plenty - always mobile is more anonymous on the web but guess what's much worse? apps.

a native app with 0 permission prompts gets you more bits than web

No. Almost everybody using an iPhone is on the latest release, plus or minus one while updates are rolling out. For a given iOS release and hardware type almost all of those probes are highly correlated. No way there’s 30 bits of entropy in that. I doubt there’s even 10.

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.