You're not understanding the complaint or you have Full Access turned on without realizing it.

Set an app like WhatsApp to No Access or Limited Access.

Now try to upload a photo into chat.

Instead of just presenting you with all of your photos so that you can upload one, you first have to click "Manage" -> "Select more photos" -> "Add the photo".

Now you can select that one photo for upload.

That could obviously be trimmed up into Grant + Upload in a single operation, but instead it's so clunky that people grant Full Access just to avoid it.

It doesn't make much UX sense since I want to push one image into the app one time, while priv granting is for future pull operations that don't make sense 99% of the time.