It's particularly infuriating because it was such a poorly-motivated change. Customers supposedly found the interaction with Google Drive confusing, so rather than improve ergonomics, they cretinously remove a lynchpin feature altogether. I still haven't found a really good alternative.
https://issuetracker.google.com/issues/112096115
https://issuetracker.google.com/issues/113672044
Google doesn't want you to be able to sync/backup your own photos anymore.