Android has a lot of nasty corners around stuff like this, which can prevent being both streamlined (accessing all photos does let you optimize for your app, some people want that) and privacy-friendly (for people who don't want that). My personal favorite:
If you don't request camera permission, you can still open the camera with an intent. This is great!
"Give app X direct access to the camera, microphone, and all my photos literally any time it pleases" and "use this camera app I trust instead" are very, very different desires.
Usually I hate the in-app cameras, because they're not optimized for my device. They're usually slower, have no flash control, no zoom, no manual exposure options, etc. I'd almost always prefer to use a dedicated camera app instead.
Because of this permissions decision, if an app wants to bake in a camera thing (nearly every app that might ever touch the camera does, even if e.g. only for a QR code reader or something), I can no longer choose. The app can't open my camera app when it makes sense.
If you don't request camera permission, you can still open the camera with an intent. This is great!
If you do request camera permission, and you are denied, you can't use that intent either. https://blog.egorand.me/taking-photos-not-so-simply-how-i-go...
I honestly can't tell if it's this way to be intentionally hostile to users, or by accident, or if they honestly think this is a positive quality.