I wanted to delete all my Google Photos after exporting them to my secret, cave safe. Unfortunately, Google doesn't have an option to delete all photos at once. What an evil move!
After some tinkering, I figured out you can simply run a script in the browser's dev console.
If you want to delete your Google Photos automatically, here's the script. Leave it running and go on vacation. It might take a long time, but it's still easier than deleting them manually.
#googlePhotos