Taco trucks make the taco on the spot. They have a full kitchen inside (compared to a ice cream truck that typically only has a fridge and a soft serve)
Based on how many people upvotes... I'm guessing people never actually interacted with a real taco truck?
Pretty sure you can't have cooking equipment turned on while driving unless you want microwaved tacos...
You either get cold food, or you wait for much longer then required to get a taco and have to spend lots more because they are burning gas to find someone who wants a taco.
Where does the electricity come from? The alternator or the gas powered generator which again ..probably can't be running while it's moving. Or do you know of trucks with battery banks cause I've never seen one yet.
Looking at electric cars, we now have access to some incredible mobile battery technology, so it would definitely be possible, and easily too. Only issue is cost, but it's only a matter of time until all or most food trucks will be full electric.
I never said it's impossible, but food trucks typically don't want to spend absurd amounts of money. That's why they have a food truck made from twigs and grease