Unlike the other dimensions, the difference between ridiculously thin and absurdly thin isn't terribly user-visible, especially given that many people will increase the thickness of their phones by more than that simply through their choice of protective case.
Does not matter, original point was that you should compare apples to apples, and comparing HTC 10 to iPhone 7 plus seems more fair than to iPhone 7 due to their dimensions.
HTC10: 145.9 x 71.9
iPhone7: 138.3 x 67.1 (-7.6, -4.7 vs HTC10)
iPhone7+: 158.2 x 77.9 (+12.7, +6 vs HTC10)