Isn’t this what the (mobile) web app is already? I deleted the app a couple of years ago and used the web app exclusively, it sheds much of the bloat (so far...).
I thought Apple is not really thrilled about the whole PWA initiative. Most of their effort has been half-hearted [1], since it bypasses their App Store (which generates a big portion of their revenue).
[1] https://medium.com/@firt/progressive-web-apps-on-ios-are-her...
Edit: Apparently, I'm wrong
The only feature that doesn't work is hold-to-slide a photo around in the editor.