> Instant money transfer means instantly draining someone's bank account with no recourse. Checks have plenty of opportunities to stop the money, so you can write a check on a Sunday as easily as a Wednesday.

This argument doesn't actually work; the period during which you can recover a check that shouldn't have been valid is (much) longer than the settlement period. This immediately shows that instant transfer does not mean instantly draining someone's account with no recourse. The recourse period isn't related to the settlement period.