But plenty of service providers, merchants, utility companies etc. will charge you a fee of their own if an auto-debit of your bank account or corresponding car

But plenty of service providers, merchants, utility companies etc. will charge you a fee of their own if an auto-debit of your bank account or corresponding card declines, or worse. While the cost is lower and the runway usually longer than a bank overdraft, the point is that it's not necessarily free to decline a transaction if it would cause one's account to go negative. I've been in plenty of situations where a $29 overdraft fee compared favourably to a $150 late fee.