X-E2s + 18-55 f2.8-4 is 659g
X-E2s + 55-200 f3.5-4.8 is 930g (edit: oops not equivalent focal length)
X-E2s + 50-140 f2.8 is 1337g
(a bit ridiculous I know)
alternatively
X-E2s + 18-135 f3.5-5.6 is 837g
There's something for everyone
Like I said though, that's not comparing equivalent combinations.
X-E2s + 18-55 f2.8-4 is 659g
D5500 + 18-55 AF-P = 675g
Even with a more equivalent lens (because I agree, the Fuji 18-55 is a very nice lens and better than most other kit lenses), it's not much more weight and you get the benefit of a more ergonomic body and a lens with greater range:
D5500 + 16-80 VR F2.8-4 = 950g
It's only 290g more.
X-E2s + 55-200 f3.5-4.8 is 930g
Is a difficult one because Canon and Nikon don't make an equivalent 55-200 F3.5-4.8. I have a Minolta 70-210 F3.5-4.5 that I use with my Sony a77, which weighs 420g, which is lighter than the Fuji and slightly faster.
X-E2s + 50-140 f2.8 is 1337g
Again is difficult because they don't make an equivalent lens. You could compare with the 70-200 2.8 which would be 2kg with a D5500, but then you've got greater range or Sigma's 50-100 F1.8 with the D5500 would be 1960g, but then you've got a lens that's a whole stop faster.
X-E2s + 18-135 f3.5-5.6 is 837g
D5500 + 18-105 VR is 890g
Canon 750D + 18-135 USM IS is 1070g
Sony's 18-135 SAM is 398g vs 490g for the Fuji.
Point is, if Nikon/Canon/Sigma/whoever made equivalent lenses to Fuji (and they do for some of them and they're basically the same size and weight) the size difference isn't massive. Most of the reduction in size and weight is in the body, but then you end up with something that's less ergonomic generally (I myself moved away from Fuji back to Sony A mount in part for that reason - big hands).
Sensor size dictates lens size, and the differences between manufacturers comes down to individual design choices. DSLR manufacturers have on the whole decided to focus on FF lenses and their APS-C lens ranges haven't been fully fleshed out whereas Fuji only has that to focus on. Look at Sony's mirrorless lens lineup for the same concentration on FF. If Fuji ever produce a FF mirrorless, I suspect they'll end up doing exactly the same. Heck, some of Fuji's APS-C lenses are already larger and weigh more than FF equivalents whilst being slower to boot (XF 90mm F2).