>>1382484I am going to make a series of videos on The Channel on that subject alone.
I don't mind FD not being as good as rear one. FD is not meant to be used consistently. To the opposite - at least on the MTB side of things, FD is to switch to climbing gears when, well, climbing is involved. Otherwise you stay on the big ring.
The upside is that on a double setup with 11 speed cassette ( say 11-32 ) you get 11 usable ratios on the big ring and of that 7-ish are in the 5-15 mph range, in which I spend most of the time. Equivalent 1xX with 11-50 ( or 10-50, if you wish ) gives me a total of 4 or so gears in that range. That is a massive loss of efficiency.
Pic related - approximate utilization of gears when I rode 1xX with 11-50 cassette and 30 ring when I rode mountains. Red - utilized, green - somewhat usable, grey - dead weight. 700g of cassette for $50. Or 350g of cassette for $200....