Yes, but it's only
slightly less inconvenient -- you can download them all in bulk (you can make the photos all appear as a folder in your drive to sync it down via the Drive app, or download them in folders via photos.google.com, or download them all via
Takeout) to your desktop PC, then ldelete them off Google, and then re-upload them using the Photos Backup tool (
"Desktop Uploader" here).