Blame ACH. It’s a putrid protocol that is far easier to get wrong than right. Once that daily file is pushed it’s a dozen people’s time to hope to fix a failed transaction, and there is no guarantee that the money will stay where it wasn’t meant to go. It’s one of those things the leaves you feeling “this needs to be better” yet it moves more money than almost any other means. All the upfront friction on users is to get it right should be some indication of what a catastrophe it is to fix.