Later this year ING will introduce instant payments. To be honest I don't remember if they will only do instant payments with other Dutch banks or also with all other European countries? Most likely it also depends on the speed of the counter party. And since those transactions will be fully automated they will also transfer cash on Saturday and Sunday.
I would say it's only a matter of time until the majority of banks will process all transactions within a few minutes or even seconds. So I would say that even if you believe that transaction speed is one of the advantages from blockchain/crypto, then this advantage will be gone very soon. Yet another reason why crypto won't become popular by the majority of people.
