> operated by the central bank
Who's paying for this? What happens if I want to spend my money abroad? Why would you assume a central bank won't be tracking us?
Visa, Mastercard, Amex, et al are all extracting profit from fees and ad-intelligence, but only about half of this revenue results in net profit. Running these things isn't free.
> you are paying more for the same thing even if you don't see it right in front of you
By extension, I infer that you think cash is free to handle. It's not.
For a high-volume business (eg supermarket, big box store), cash is an absolute nightmare. Counting at the point of sale, counterfeiting, storing, balancing and float management. That has time cost, while mistakes at any point have direct monetary costs. A 2% card fee compares pretty favourably, especially if you go cash-free.
I welcome any disruptors, but we need to be realistic. Given the awful history of simple bank transfers in the US, I wouldn't be expecting the answer to come from them.