Problem is that U.S. credit card fees to banks, Visa, Amex etc. are way too high to vendor. Around 2% more or less with higher fees for reward cards. This does not reflect cost of running system, but, more, oligopoly rent extraction (including our much beloved credit card miles bonuses

).
In other countries (for example, France), reflecting the actual tech efficiencies and other factors merchant fees are very low, approaching zero in many cases.
In the US, government "vendors" are often prohibited from accepting any thing less than is owed, thus, no payment by, say, local property tax collector, to card company is permitted. You have to pay the "convenience" fee if you want to use a credit card.
In other words, don't hold your breath waiting to be able to pay your property taxes with your credit card without the added fees.