I used to pull a 6500 lb trailer with a truck that weighed around 4600 pounds. Power and braking weren’t the issue - rather the trucks ability to remain settled with all that weight back there was. That was a Gen 1 tundra. It was rated for 6900. Upgraded to the f150 which did a much, much better job. I would not want to pull much more than that with an f150 on the interstate. Again, power and braking isn’t the issue, it’s the vehicles ability to stay planted and manage the motions behind it. Most RV guys start looking at 3/4 tons around that threshold.
we all know of that one instance where someone put a lot of weight behind the truck during unusual circumstances and it did fine… often for 9 miles at 45 mph. But that’s different than 6 times per year over several hundred miles. I do know a half ton owner who pulled a 32 foot travel trailer, and it was way too much for the truck. But he did it only 2 times per year, all back roads, and all under 45mph.