Traditional banking is sufficiently slow enough that things can be reversed before permanently settled. The "slow" speed of moving money is a feature. It's designed for humans who make mistakes all the time.
We also don't even need to change this aspect of traditional banking in order to add strong asymmetric encryption in front of the system. That would nip most fraud in the bud, and if nothing else save a lot of effort that goes into fraud schemes, prevention, and reversal.
Large business transactions generally (not always, obviously) do not have the sense of urgency that would require fast settlement. There's some market maker stuff that benefits from fast settlement, but that's not exactly a reason to push whole new system out to everyone.
The biggest "benefits" of crypto are not benefits to the average consumer going about their daily life. Instead of dealing with fraud you'd have to deal with customer service issues for actual customers who forgot/lost their keys. And, honestly, you'd probably have to deal with more fraud. Your phone gets hacked, your keys get stolen, and then what… all your money is irreversibly gone?
Why would they expect this? It seems like the slowness is the only thing keeping the game from growing legs and walking away from the humans playing it.
Making things faster will be good for some people, bad for others. Not clear if better on the whole.
It’s also probably better to keep it slow to prevent impulse decisions (let me put all of my money into dogecoin, it’s mooning now)
If there were more of a delay, like the maturity rate of whatever bonds, SVB would be fully functional today.
FTX, as long as nobody looked too hard they probably could have lost the few billion they had left while keeping everyone happy.
Bank runs… always blame the customers.