One of the first things I do when setting up a new Android device is turn off backup in the Google Photos app, so you can imagine my surprise when I created an album to organize some photos only to later see cloud storage for my Google account go from 0 GB to 1 GB. I deleted the photos from the Google Photos website thinking I must have made a mistake. I double checked my backup setting, which was still off, and created a new album, but this time only adding a single photo. Sure enough, both the album and photo showed up on the website again.

After a bit of searching, it appears this is by design, since albums are specifically a "cloud" concept, and they don't exist locally on the device [1][2]. Of course Google never mentions any of this when creating albums or adding photos and videos to them, so to anyone using albums in the Google Photos app with backup turned off: all of your photos and videos are still being backed up, and there's nothing you can do about it short of deleting all of your albums and any photos and videos in them.

[1] https://support.google.com/photos/thread/147486

[2] https://support.google.com/photos/thread/119437539