I have had 4x4 on my last 3 trucks. Not because I particularly wanted it, but because it is near impossible to find a higher trim level truck with the options I wanted on dealer lots. I have never used 4x4 while towing. We occasionally get a little ice, sleet, or snow and when driving around I typically do not even engage it for that. I don't off road. And our RV trips are almost always at parks with paved, gravel, or rock pads. Only time I have ever actually NEEDED 4x4 is getting in/out of muddy pasture roads to our hunting cabin. And then only in those few times it was overly muddy.
I drive a Ford and the Ford F350 4x4 is quite a bit taller than the 4x2. The newest ones probably too tall for my 5er.