Separation seems to be enough for me, as long as I can browse cloud images. The cloud does not need to be parsed for tags or “All Media”, which would be a huge performance drawback using Webdav.
What could be useful is moving from or to cloud.

To be honest it’s not the best solution to have the Webdav credentials in all single apps like FolderSync, Solid Explorer, and then fstop. A system-wide webdav mount would be better, but it’s the current way that apps need to access Webdav themselves.