I agree with everyone that the 4runner is a truck, is 4700+lbs, has a long geared 5AT, and is lacking in torque and/or torque multiplication, BUT it still doesn't explain to me why I can be in CC and apply some steady and minor throttle when going up an minor long incline and the truck will rarely downshift into 4th and will never gear hunt. It sometimes unlocks the torque converter which provides MORE TORQUE MULTIPLICATION! What a novel idea?! Yet when leaving CC to full control, it doesn't want to unlock the TC in 5th, but rather downshift. It makes no freaking sense that they can't at least lessen this issue with a simple shift logic reprogram. This is 2021 after all.
Driving in the hills of northern Arkansas made me appreciate driving in 4th and even sometimes 3rd. A running speed of 2200-2400rpms seems to be the sweet spot for this motor in terms of response, smoothness, and mpg assuming you're having to deal with some minor topography. We saw nearly 20mpg in driving in the winding hills with a good amount of coasting followed by heavy throttle to climb. I never thought 20mpg would be possible, especially in hilly driving. Speeds ranged from 30mph to 65mph and we did 200 miles in the area. Then we head home on the interstate at speeds of ~75mph and saw 17.0 mpg. In the 4runner's defense, it did have a paddleboard on top and facing a cross wind of ~15mph.
Don't get me wrong, I do love the truck and my wife (her truck) absolutely loves it. Interstate driving just isn't what it's good at. Unfortunately for us, we have to do a lot interstate driving to get to fun places.