[abalone]

There's basically two reasons for that. One, 2.9% is only standard with premium processors like Stripe and Square. They charge a premium markup over interchange. You can still find "interchange plus" processors which will be much more value priced, although they usually are not as easy to work with.

Two, the underlying interchange rates have risen since the 90s due to reward cards. It's more expensive for merchants, but a lot of that goes into customer pockets via reward programs, so it's somewhat debatable whether it qualifies as price gouging since it's driven by consumer choice.