well, time to downgrade my iPad from 26.4 back to 26.3 while i still can because of course apple didn't put "btw we're doing UK age verification now" in the patch notes
if you don't verify you're over 18:
browsers will block 'adult' websites - this appears to affect all browsers (not just safari) and can't be circumvented via a VPN, it seems to be blocked at the webview level
if you use safari extensions, you can't configure them any more
a little red notification badge on the settings icon until you verify
presumably a bunch of other bullshit too