I would say one day we'll see an exchange or at least a financial institution with a crypto exchange arm that'll get a true banking license along with the deposit guarantee schemes that all national banks get from their respective countries. Then I might say that's as safe as it gets (since with that guarantee it also means you open yr books to the central bank, though we all know that's not much in way of safety these days).
That would be so interesting to see , I guess this would be when regulation is in place. Therefore the only time I think this exchanges will will be total safe is when there is proper regulation, hence no one is gonna ever have faith in any centralized exchange even with the platforms that seems to be safe , like Binance and Coinbase. So with these happenings around centralized exchange safety will only come in if there's regulation in place.
And I think it will come close to such a time. There are already some banks that have more or less become crypto custodians. Bank Frick in Lichtenstein, an example I can think of but that is a small bank, old money, old family, high gdp country.
I believe there are other large entities going the route I mentioned, already crypto custodians either applying for banking license or just buying out a bank. Nexo at least is one such company but they bought a controlling stake in a fdic member so probably does not count.
Again, bears repeating that this only increases safety. Will never come to the level of assurance of owners keeping sole custody.
