They are massive because of the cafe standards. There's plenty enough of a market for smaller trucks, even the Ford Maverick which is closer to a car with a bed sold out immediately.
I like my big truck but when it dies, if there's a small truck available that lets me plow snow and tow logs in the forest, I'll get it.
Smaller trucks don't have the suspension etc. for mounting a snow plow, or heavy towing. Those are applications where a bigger heavy duty truck make sense.