https://youtu.be/TnM1ooYKN_Y
The you tube video is of Taylor Dzaman he has a camper with a gas chevy truck, in this video he has a friend has the same camper but with a diesel chevy , he drives both and gives his opinion.
This guy has lots of truck camper videos, mostly I would say they are good and seem pretty unbiased.
The idea that the diesel will give you more longevity with more miles is probably true but..... I would not get all excited about it, gas trucks these days seem to go 200k plus. Most trucks, especially the ones used for recreational use will wear out the truck before the engine.