Earlier quoted context omitted.
I’m a big fan of the capability-based photo access in ios; when an app tries to access my photos it opens a system dialog which allows me to select the set of images the app can see.
Have you ever tried to build a cross-platform photo app that works on iOS and regular computers?
That said, it's not:
(a) as if there aren't cross platform photo apps that run on iOS and "regular computers". Photoshop and Lightroom come to mind immediately, Affinity Photo also. And those aren't just iOS and Mac, they're also on Windows. So there's that.
(b) as if what would slow you down / prevent you from doing such a cross platform photo app would be the iOS capability / image access request feature.