There is very nearly zero usefulness to overdraft protection in a real-time authorization world. Nobody charges a fee for a rejected debit authorization.

I suppose merchants might charge a return check fee for a failed ACH payment, but nobody uses ACH payments for anything routine in the US.

Water bill, electric bill, mortgage, and property taxes are all ACH for me. Many people pay rent that way. I don’t think it’s commonly used for day to day interactions but a lot of payments are still ACH

It's more handy for gas pumps, but less transparent. It stops before your tank is completely filled, but doesn't say why. You can hear the difference if you are standing there while it fills, of course, but other than that you may be confused why it slowed down and stopped exactly at a certain amount and won't go any farther.

The way it works in NL is you pay a (high like a creditcard) interest rate for every day the account is below zero. The transaction order doesn't matter it looks at the balance at the end of the day and charges you 1/365th of 13% interest.

The only way banks fuck you over in this system is with the dates. Using a card means a transaction date of "today", getting paid almost always has transaction date tomorrow. So you end up paying 1 day of interest. Much less than a $ 40 overdraft fee and regardless of the number of transactions.