Despite some misleading pictures shared on social media, if you do an apples-to-apples comparison (e.g., a 1972 F-150 and a 2023 model with the same bed size), they are about the same length. The differences are vastly better driver safety and fuel economy.
The main difference is that nowadays, there are more factory and aftermarket configuration options available, and people have more money, so you see more people driving heavy-duty trucks with 35,000 lbs towing capacity, which have big engines and thus are rather beefy. But conversely, you also see more people buying small trucks with "stub-length" (4-5 ft) beds.
It's interesting that you don't really have a market of mini-pickups that are seen in Japan, but that's probably partly a matter of weird fuel efficiency regulations, of import restrictions, and cultural factors (few people in the US want to be seen riding anything golf-cart-sized, and it's not exactly a guy-only thing.)
Driving a kei truck is basically the most fun you can have with your pants on and they get a smile from everyone. AIUI, it's primarily the safety regulations that make them unsellable new in the USA. The crumple zone is the drivers knees, just like a VW microbus.
Old ones can't be registered in all 50 states. New Hampshire will let you register one; Vermont is not as accommodating. They're also pretty pricey for a 25 year-old car.
Oh, and they top out at something like 50 mph. Which would be terrifying if you managed to keep your foot planted long enough to get up to that speed.
I've driven one that was a summer camp vehicle, and I'd love to have one, but I live on the wrong side of the Connecticut River :-(
I know what it's like to be in the presence of a typical old truck, compared to a typical modern truck. The modern truck is wider and taller, accelerates faster, and has worse visibility. I'll trust my own eyes and experience over some conveniently angled photos and irrelevant "apples-to-apples". (To extend the analogy: you're doing your comparison using a cultivar hardly anyone buys anymore).
Even the differences in height are often overplayed by making bad-faith comparisons: https://i0.wp.com/www.curbsideclassic.com/wp-content/uploads...
The main difference is that nowadays, there are more factory and aftermarket configuration options available, and people have more money, so you see more people driving heavy-duty trucks with 35,000 lbs towing capacity, which have big engines and thus are rather beefy. But conversely, you also see more people buying small trucks with "stub-length" (4-5 ft) beds.
It's interesting that you don't really have a market of mini-pickups that are seen in Japan, but that's probably partly a matter of weird fuel efficiency regulations, of import restrictions, and cultural factors (few people in the US want to be seen riding anything golf-cart-sized, and it's not exactly a guy-only thing.)