Comment by heavyset_go

I left an iPad on a shelf for more than a year. During that time, Apple must have done migrations with iCloud and Apple accounts, and completely deleted the account the iPad was signed in under. I couldn't unlock the iPad, and I even tried re-registering a new account using the same email address and password that I had originally used. Didn't work at all, and it's still a paperweight.

I'm just lucky in that I didn't have any important data like pictures, passwords or 2FA apps on it. Sorry for your loss.