The current Hilux is extremely close in size to the US Tacoma... It has also grown over the years. Although if you look at the footprint size (e.g. what CAFE measures), the Tacoma has the wheels a little more advantageously placed.

I am sure they could consolidate the models to work in both the US and abroad, but my guess is they do enough US volume that it is not yet advantageous to do so. There's already a number of major parts that have been shared recently between the Tacoma and Hilux... e.g. the 2TR-FE engine and AC60 transmission. But usually Toyota chooses to spec the Tacoma as a more up-market vehicle, which makes sense given the US market.

In 1993 I paid a shade under $10k for a new Chevy S10 where the only options were AC (not actually optional in Texas) and CD player in the radio. It was manual transmission, V6. Indexed to inflation that would be, what, about $24k today if regs allowed them to be built?

If it existed they would fill every rural high school parking lot in the south. Allow them to exist and someone will build them.

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.