Somewhat related, but I find it hilarious that the mobile game devs Com2us has better security protocols than Blizzard.

My Blizzard account also got hacked at some point in the past year (no idea how, since it didn't share a password with anything else that I owned. I have since reset all my passwords on every account I own and set up 2FA for those that support it)

I emailed Blizzard about it, and they didn't require any proof of ownership. I literally just submittied a ticket saying

"This is my account username#1234. I have noticed it has been hacked and then banned and would like to try and recover it."

It took 2 months for support to reply, but they did just that.