As far as why you can’t export your edited photos, is that iOS doesn’t actually exit your photos. It applies the edits from what I can tell as a separate “filter” that’s stored as metadata so you can undo your edits. How do you export your edits in a cross platform way? Would you rather have destructive edits? Maybe you would. But either way there are tradeoffs.

And files have a different data store than a photo.

You just plug any mass storage device into your iOS device and it shows up in the Files app and you copy and paste files like you would in the Finder or Explorer. In fact, in the Files app, if you have a third party storage service like Google Drive or Dropbox, they also show up as location in Files along with iCloud. Meaning you can copy directly from Google Drive to your mass storage device.

You can’t do that with any random “file explorer” on Android - ie a consolidated location for local storage, cloud storage from 3rd party providers, network connections, and mass storage.