Several things..
Probably said a million times, but far and away the biggest for me, a universal systemwide back gesture a la android. This would make life so much easier. Eg swipe from the right of the screen with my thumb. I’ve just gotten stuck viewing an image attachment in Telegram as it had gone full screen and there was no way out except swipe out entirely to the home screen, close the app, then reopen. I’m right handed and if holding one handed I can’t reach far enough to swipe from the left, in say settings. Regularly having to go to either top left or right to click some button in an app is jarring and inconsistent, in fact the whole thing is ridiculous for an os that’s meant to be intuitive and user friendly.
Not v likely to happen, but an accessible file system.
Browsers other than those based solely on Safari. I need ublock origin and sponsorblock in my life as it’s extremely difficult to tolerate browsing without them after using for even a short period. I know there’s Hush and various blocking addons for safari, and the Orion browser, but they simply don’t work correctly/fully.