It’s clear that I’m in the minority with this opinion, but call it food for thought…
Virtually any small car can pull 1,000 lbs. An inexpensive trailer (harbor freight has several for under $300) fits more bikes and gear than a pickup bed, and the 99% of your driving that you’re NOT pulling it, you get much better gas mileage than a pickup.
I would not advise towing with a CVT (and I’m fairly certain the OP’s corolla has one), but when I owned a pickup truck, the bed was usually empty. I got 16-18mpg in mixed driving. With my current car (’03-’08 corolla), I can fit 4 people a lot more comfortably than the Ranger ever did, and the car will pull 300 lbs. of trailer, plus 300 lbs. of dirt bikes, 100 lbs. of cooler & drinks, etc. without breaking a sweat. It would probably struggle in the mountains with the motorcycles, but not with bicycles…
Average economy with my car is 34.2 mpg (I’ve tracked over 40,000 miles with fuelly). That number drops to about 30 when towing.
Does that make my corolla the “ideal” mtb vehicle? Hell no! But I am not in the camp that thinks a pickup is necessary, or “ideal” either.
IMHO, the ideal MTB vehicle is capable of fitting 2 bikes inside (for security), has AWD to get you to and from remote trailheads, and gets 30+ mpg. I’m pretty sure I just described a Subaru wagon. Choose your own variation. Any of their vehicles can tow an open 4×8 trailer with 4 bikes and tons of riding/camping gear for you and 3 of your friends in the wagon. I bet it would probably get 28ish mpg under those conditions, and surpass 30 in everyday driving.