Kraken has been operating under the money transmitter licensing scheme for a decade, and like banks, money transmitters don't have any legal requirement to segregate customer funds—although they do have the responsibility to maintain sufficient cash balances or liquid investments to cover all of what they owe to customers.
I think you meant to say here and unlike banks, because banks absolutely do not need to have sufficient funds to cover all customer's savings.
Unless.. are things different in the US? It's been a decade since I've read the Bank Act (Canadian), and when I did, only 5% of customer's account holdings were required to be held in tangible assets (gold, cash, etc), and inspected yearly by the Minister of Finance.
And I believe even that requirement has been dropped.