How to delete all photos from iCloud library without having to manually delete every 1000 items?
Deleting photos is easy if you can borrow a Mac.


https://apple.stackexchange.com/a/179483/5472


If not, you’ll want to pick away with it or open a support case with Apple. The engineers can blow away files if you give them a support PIN and they have a reasonable belief you can’t do it by plugging away with the tools Apple ships and you realize the limitations are there to prevent a moment where someone destroys another’s library when their phone is unlocked and not hassle someone that legitimately wants to remove thousands upon thousands of photos.