Progressive Web Apps on the open web are an attack on Apple's App Store.
Apple is fighting back - https://andregarzia.com/2020/03/private-client-side-only-pwas-are-hard-but-now-apple-made-them-impossible.html
I totally removed Safari support for Signup. Wasted many days to make the new fantasy ITP Storage Access to work. It's totally out of sync with how other browsers work