Since nicehash got hacked in 2017 i look at coinbase and they had 90% of ther coins in cold storage and i was okay whit loosing 10% if they got hacked
This would only ever protect you if Coinbase's main wallets and servers were hacked directly, which is the the least likely attack vector. It would offer no protection whatsoever if your individual account was hacked, phished, password reset, etc. It also offers no protection against Coinbase themselves locking access to your funds as you have just discovered.
I use to be they guy that tought coinbase only locked account for drugdealers and scammers!
They lock a lot of accounts for unknown reasons. They are not very transparent with their automatic algorithms or processes which flag accounts up as being "high risk" but things as simple as withdrawing to a gambling site will get your account locked.
i will post again here if i get my account back and how long it took!
Have you tried contacting their representatives directly using the reddit links I gave above? Or opening a new thread in the /r/coinbase subreddit?