jillyboel parent
It's designed to sync the files the user wants synced, be it files produced by the camera app or some other app that operates on a directory on your device, such as your Downloads folder, audiobook folder used by your audiobook app, or the notes folder where your notes app writes the notes.txt, or just straight up everything.
It can do that just fine with the new permissions, you just can't sync the root folder or Downloads folder which is OK as documents, audiobooks, etc would be stored in their respective folders and not Downloads.
You mean that that's ok for you. Which is fine. It isn't ok for other people, which is also fine.
Some people may not want to have to reopen Nextcloud any time a new directory appears on their device so they can add it to Nextcloud, while the other American bigtech backup apps can just pick it up automatically no problem.