Which makes perfect sense for face to face QR payments, as that's a very low risk payment system, in a situation with minimal fraud. Therefore, you go through a system with minimal fees. Moving far away from the expensive payment systems makes perfect sense there.

But this article's headline is already lying to you, because when you look at the table, yous ee that Stripe and Braintree include the interchange fee, and Adyen won't.

See how the Stripe percentage there does cover the entire interchange fee already. In many an online store, your median interchange fee, which is set 100% by what card the customer is using, is probably going to be over 2%. So 0.6% + interchange fee might even be cheaper than Adyen.

So the real argument IMO is whether it really makes sense for the US to keep bribing customers with points and cash back to keep people using expensive credit cards, vs the regulation in other places that limit fees, and removes most credit card bonuses, other than paying at end of month. But that's up to congress.

Are restaurants directly using Adyen? I assume it’s some point of sale system like Toast or Square that’s using Adyen and all of them are using that POS system

How can you tell that they're all Adyen? It's not like it shows on the statement descriptor.