Interesting, so I looked it up. The best discussion of the issue is
HERE which is updated to Aug 2021, so a year old.
It says that Florida is not enforcing the law against this practice, as above. It also gives the rules which define how a merchant must notify the customer. These rules come from the card issuer, eg VISA and M/C.
Importantly the store may NOT charge a fee if you use a debit card, only a credit card. They may not profit from this fee, they may only recover up to the amount they pay the bank. The consumer must be notified in advance of purchase that such a fee will be imposed. This may be a sign at the entrance or a notice on the menu. The first notification cannot be on the bill you received after the meal.
The merchant must notify in writing the credit card company of their intention to impose the fee.
It is an interesting article, I don't know how accurate the representation of the rules are in the story. I don't think as a customer we have any way of knowing what the actual fees the bank has charged the restaurant may be, although 3.5% is at the very high end of what a restaurant might be paying. I have no idea how one would know if the bank received the required prior notification. As a customer you should be able to know if you saw a posted notice of this fee. And if you have a debit card and want to use it in this situation you will save a few dollars.