Except that major banks now can and do. The "Zelle" network contains thousands of member banks and moves money instantly between accounts. The limits on amounts sent vary (my Wells Fargo account can send to my friend's Bank of America up to $2500 a day, no fees).

The claimed advantage of crypto is that there's no oversight or limits on the amount you can send, whereas banks report any transaction over $10k (or something like that) to the IRS.