Are there some abusers of the exemption out there?

I kinda like smaller orgs getting a small leg up against bigger ones. Discourages excessive consolidation. It’s like an anti-oligopoly provision.

Before Durbin there used to be a lot of banks that offered points-earning debit cards. After Durbin, for many years SunTrust had a debit card that earned Delta miles. I think that's since moved to Truist. [1]

I guess it depends on what you mean by 'abuse.'

Is Truist abusing non-Durbin status by giving out points for PIN debit transactions? Or are all the other non-Durbin banks who give back nothing abusing the exemption by keeping the interchange?

[1] https://www.truist.com/checking/debit-cards

Being non-Durbin enables Truist to compete with bigger banks by being able to offer things like cash back on debit. That seems less like abuse and more things working as intended.

From what I can tell, the exempt interchange fees were unregulated. So don’t know if they went out of control or not.

But even Durbin wasn’t perfect: before many cards would charge more of a percentage model, but after Durbin, raised them per swipe fee to the max. Which can be unfortunate for small purchases.