Fares are whatever can be stolen.
No. Taxi fares are actually set. They're hard/impossible for occasional users to know without reference to a site like Ric's, so taxistas charge whatever they think they can get. That's not actually the "fare", though. It's just the charge or "whatever can be stolen". Whether or not we agree on the semantics of "fare", we agree on taxi drivers' dishonesty, though you're considerably more enthusiastic about using taxis than I am. You went to all the trouble to hike to Diego's and negotiate yourself a ride 44% (92 pesos) higher than the maximum shared shuttle fare of 208 pesos. (Since I don't know the zone for where you were going, I'm just using the highest possible fare. The difference could've been more). That's some taxi-lovin'!
Fares
from the airport (which was the subject of the message to which you responded) are set, published right at the point of payment, and they're not open to negotiation, "bribery", nor (non-willful) misunderstanding. Who tried to dicker with you about shuttle fares from the airport terminal? You can't even pay the drivers directly! The payment window gives you a printed receipt so you can confirm you paid no more than the published fare.
I walked ACROSS THE STREET from the tiny airport and caught a cab. I didn’t cross a superhighway a mile away.
You are willfully wrong, ACROSS THE STREET from the terminal is the parking lot. One must walk past that then down a short road to exit the airport grounds, then cross the street. Nobody said it was a superhighway. It's also not merely crossing the street. It's about 300 meters, roughly ⅕ of a mile, and involves crossing two roads. That's a trivial distance for some. It's a substantial hurdle for others, especially with luggage, kids, mobility devices, whatever. Not everyone reading these posts in the future will ever have been to Cozumel before, so I think it's important to be clear about what we mean. Imagine someone walking across the road from the terminal and searching in vain for Diego's while muttering "but they said it was across the street!" under their breath.
I have no idea what you’re talking about. Taxis do whatever they want .
In order to get an idea, you could try reading the posts to which you're responding. There are no taxis that can pick anyone up at the airport terminal so, for purposes of fares from the terminal, taxis and their unarguable shenanigans make no difference. With the shuttle vans there are no shenanigans, just (in the case of private shuttles) extortionate but completely transparent pricing,.
I know that as a local you must support the locals against the gringos.
You have clearly paid no attention whatsoever to what I've said about taxis. In this exchange, you are the only one of us who's expressed the slightest enthusiasm for them.
for someone in a wheelchair they may need to pay the bribe.
What bribe? Airport shuttle fares are clearly posted and are not subject to negotiation or bribes. For a single traveler willing to share a van, they're also cheaper than one is likely to get a taxi to agree to (as we see from the example you posted earlier). In fact, you get a receipt proving there was no bribe involved.
Does your mom often come to Cozumel?
She's cut back to 3 or 4 times a year ever since CoVID. Why do you ask?
You should be aware that lots of divers arrive with non-diving family or friends with all sorts of degrees of mobility, heat tolerance, or willingness to get drenched in a downpour. I usually travel to the island with just a messenger bag, but am aware that's uncommon and that some people appear to arrive with enough luggage for months in the wilderness, or certainly more than they can themselves carry.
Why would I do that? I have my own perfectly good car. When I'm leaving the airport, it's parked right
across the street! I then get in it and, usually, drive to Diego's, which takes about a minute.