If I were a fulltimer, or close to fulltime, but not moving very often, I might consider a residential fridge. As a longtime traveler moving very few days I'm thinking all of that jiggling & shaking is going to shorten the life of a residential fridge considerably & any savings gained by buying one will be quickly lost having to replace it way sooner than a made for travel RV fridge.
Then there is the power side of it. You either need to be tethered to shore power 100% of the time or either have a genny that costs $$ to buy & run or have a large battery bank plus pure sine wave inverter to run it when the genny is off. Solar power is an option too but that is not much use if you like camping in the trees. All that stuff costs plenty extra $$ also & all has to be figured into the mix.