Many people like the classic folding medium format cameras, because they offer medium format quality in a small package that can fit in a coat or a briefcase pocket. A new folder can offer modern attractions like modern optics and coatings, a new shutter, less squinty viewfinder, an internal meter, 120/220 frame counter instead of the red window, more rigid construction, and superior film flatness, in more or less the same compact package as the models from the 1950s.
MF rangefinders like the Mamiya 6 and 7 are great cameras, but aren't as compact as a folder.