Many good points - however
A very good medium format camera remains a heavy bulky camera. For a planned trip where the photography is the object of the trip the bulk and weight may well be acceptable. For any other purpose the weight and bulk are likely to be unacceptable. A moderate camera that you have with you is better than a superb camera that has been left at home.
Rough comparison of camera weights
Camera part of smartphone - under 10 grams
Compact zoom camera - about 150 grams
SLR with APS-C sensor and kit zoom lens - about 700 grams
Full frame SLR with good zoom lens - about 1500 grams
Medium format camera with lens and tripod (needed) - about 5000 grams
I have a number of lenses that I use with my full frame SLR but the one that gets the most use is a good quality 35-200 f4.5 zoom. Other lenses (50mm f1.4, 500 mm f8 mirror, 135mm f3.5 etc) are used for some preplanned shots but are not normally carried due to the additional weight. For a person who is not a professional photographer, the weight of the carried equipment is a very important consideration. (For a casual trip into London, if I carry a SLR camera at all it is likely to be a Sony A200 (APS-C) with 18-70 kit zoom for its light weight.)
I have considered and could afford a medium format setup - however I decided that it would not get very much use due to the weight so I decided not to go for medium format.