Something that custodies money should be able to give it all back instantly. If it is vulnerable to "fear uncertainy and doubt" as a self fulfilling prophecy of not being able to pay out everything instantly, then it should be dismantled.
I think its interesting that properly collateralized and well managed services don't make the news, but it is very common in the crypto space for 100% withdrawals to occur seamlessly. Far more common than the implosions. Whereas seemingly all banks are relying on withdrawals en masse simply not happening.