645 -> why use it when you go medium format ?
35mm -> boring indeed, not wide, not a portrait focal, can never get it to fit my style.
28mm -> not very impressive as a wide angle lens, prefer 24mm or 17mm
Zone system when you are shooting everything
but large format.
My 135 f2.0 L (canon) sees way less use that my other lenses, but I think it's because my 70-200 overlaps, and I rarely need f2.0. (Should probably have saved my money back when I bought it ^^ )
Sigma 50-500 -> you either use it on 500 or use other lenses. Who shoots portraits at 50mm @ f6.3, with a lens that weigh 1,2kg ? (Sold mine, bought the 400 5.6L).
28-135 IS -> old Canon lens that was never wide enough or long enough (and too slow)