As a trailer guy who routinely takes his trailer into some fairly rough places, there is no doubt that a truck camper can get into places that I can't reach with the trailer.
But there is a counter-argument: it is not so easy to take the camper off a truck and put it back on. We almost never see campers sitting on a campsite on the legs, without the truck. So the real question is whether the truck camper (as a unit) can get you where you want to go.
That is one reason why we opted for a small trailer: we put the trailer into a reasonably remote "base camp" and then use the truck as our exploration vehicle. We take the truck to really rough trailheads, places that most TCs would not go -- too narrow, too slanty, too many overhanging branches. (Jefe is an exception -- there is no place he can't reach.)
Bottom line -- there is no unquestionably-right answer to the OP's question. The answer depends on what you intend to do once you arrive at your campsite.
