You can compare it to a creditcard payment, the transaction takes places almost instantly.
With a creditcard sweeping your card only confirms you have the funds to pay, but the actual payment is done days later and can be charged back up to 90 days.
If you're trading for a lot of money waiting for a couple confirmations is in fact really short comparing it to other payment methods.
That's not exactly comparing like with like. The credit/debit card system is designed to operate this way.
A better comparison is a bank transfer which, here in the uk, usually only takes a minute or so.