Lots of people want full-sized pickups, unfortunately. The F150 has been one of the top selling vehicles in north america for literal decades, and while it used to be smaller, it's been pretty big for at least 10 years.
But the Lightning is SUPER expensive and a lot of the folks buying full-sized trucks are doing it for the optics. They want to appear tough and rugged, and they can't do that without a loud engine, I guess?
The depreciation on EVs is also astronomical. Pay $100k for a Lightning and it'll be worth $60k next year. There's no point in buying a brand new EV right now.
I agree that people SHOULD want smaller trucks, or—get this—CARS, but the big car companies love their margins. Ford's eliminated every passenger car in their lineup except for the Mustang (even the Mustang Mach-e is classified as an SUV for some reason).