How many years before this happens in parts of the United States?
The right question to ask is whether places like Mexico are going to politely wait for the US to get its act together or whether they'll just go ahead and start electrifying their country and industry and reducing their cost levels. The current isolationist policy works both ways. Very sunny place, Mexico. Great place for solar and batteries. And once you have those, Chines EVs produced locally might work very well. And they can export those further south.
The US importing synthetic fuels is not going to be a huge market for economic reasons. There's no logical reason for tax payers to pay Mexicans to make really expensive fuel for them. Just so they can pretend battery electric doesn't work north of the border.
Synthetic fuel at scale is just really expensive. And battery electric is going to take a sledge hammer to any misguided plans around that topic. It's going to get progressively more awkward to build a case for that. All those things where people still hang on to the believe that "surely batteries will never work here" are going to melt away over time. Batteries are going to get a lot cheaper and better over the next decades. And they are pretty good already.
Your mention of aviation fuel is relevant. That's a context where batteries are not pretty good already, although they are viable for short hops; in aviation, as in shipping, heavier batteries create more energy consumption, so a carrier with a higher specific energy per kilogram is very valuable. Conventional jet fuel is 43MJ/kg (https://en.wikipedia.org/wiki/Energy_density#Chemical_reacti...) while lithium-ion batteries are up to about 0.8MJ/kg (https://en.wikipedia.org/wiki/Energy_density#Electrochemical...).
Very crudely, an airplane whose weight is mostly jet fuel can fly about 50 times as far as a rechargeable-battery-powered airplane if both are going the same speed. Rechargeable batteries are 50 times worse than jet fuel. And they're improving slowly; the last time that difference halved was with the invention of lithium-ion battery, which went mainstream about 30 years ago. The previous major improvement was the lead-acid battery 120 years earlier.
However, promising alternative synthetic fuels other than paraffin include aluminum, magnesium, and zinc, which can be burned in aluminum-air batteries, magnesium-air batteries, and zinc-air batteries, respectively. Aluminum and magnesium are 31.0 and 24.7MJ/kg, respectively, but burning them in metal-air batteries instead of in heat engines allows you to extract about twice as much useful energy from the reaction, so they are in practice higher in energy density than current jet fuel.
Current aluminum prices are US$2828/tonne (https://www.lme.com/Metals/Non-ferrous/LME-Aluminium#Overvie...) which works out to 9.1¢/MJ. A barrel of oil is 6 gigajoules (https://en.wikipedia.org/wiki/Barrel_of_oil_equivalent) and US$58.78 (https://www.cmegroup.com/markets/energy/crude-oil/light-swee...) which is about 0.98¢/MJ. So the price of aluminum would have to drop by about a factor of 5 to make this appealing. It's plausible that this will happen, but not before 02040.
Magnesium is 17050RMB/tonne (https://tradingeconomics.com/commodity/magnesium), which is US$2410/tonne, working out to 9.8¢/MJ.
Batteries are the invisible change in the power business. They don't take up much land area. They're not visible to the public. Just being able to charge batteries during low power cost periods changes the whole economics of the industry.
Whether battery banks should be allowed to sell back to the grid is a tough question. Texas says no.[2] It's potentially "dispatchable" power, but only until the battery runs down.
[1] https://www.latimes.com/environment/story/2025-10-17/califor...