Yes, but their energy density has hardly changed and every gasoline tank beats your average LiIon battery by a factor of 10: > https://en.wikipedia.org/wiki/Energy_density#In_chemical_rea...
But lets look at actual mileage at two roughly comparable cars (same vendor and brand):
Mustang Mach E 88kwh/300 mile EPA range. Or about 3.4 mile per kwh.
2021 Ford Mustang Mach 1 does 5.6 gallons per 100 miles (with the 8 cylinder engine). Or about 18 miles per gallon.
https://www.fueleconomy.gov/feg/noframes/43610.shtml
These are just official numbers, take them with a grain of salt. Also, both cars have a couple of variants obviously. Particularly the petrol mileage is likely to get a lot worse over the lifetime of the car as the engine wears out. This is less of a thing with EVs. And you probably have to drive the petrol Mustang like a nun to actually get 5.6 gallons per 100 miles. Likewise EVs have different mileage depending on driving style, temperature, etc. Lets just say they are both a little bit worse typically.
But they are nice numbers to work with and they are based on real world efficiency rather than archaic notions of potential energy, energy density, etc.
With these numbers, 1 gallon is roughly the equivalent of a bit over 5kwh when it comes to mileage in a gas guzzler like the Mustang. Cost for that from a super charger depends on a few factors. Likewise for a gallon of fuel (e.g. taxes). On a super charger at 28cents per kwh, it's like filling your tank for about 1.40$ per gallon , which would be a pretty good gas price that most of the world has not seen in a few decades. A super charger is probably the most expensive place to get your electricity. So, you might do better if you have cheap nightly grid rates or rooftop solar. There are lots of ways to get that number down. But 1.4$ per gallon equivalent is a lot cheaper than petrol. About 2x depending which state you live. Closer to 3x in some states. EVs are a bit heavier than petrol cars of course. But not 10x. Nowhere close to that. Maybe 1.5x or so. Half the energy cost per mile at the price of 50% extra weight is not a bad choice.
That's the reason people are switching to electric. It's just cheaper. It gets better when you also consider maintenance cost. It gets better still when battery and vehicle prices continue to drop. Purchase price of EVs is currently still slightly higher than the equivalent petrol car. But not for very long apparently.
Your mileage may vary but nowhere near 10x. More like 0.5x.