Let's face it, very little people need the entire hardware set of the Helix Floor. Mic and Variax inputs usually are wasted, even SPDIF doesn't seem to see any use with most folks. Capactive switches aren't needed in case you have a touchscreen and most people likely get away fine with one FX loop. Add to this some Helix components aren't exactly military grade, to put it carefully.
And as far as onboard expression pedals go, there seem to be plenty of folks who rather would not have them (fwiw, personally I love them because it's easy to realize wah/volume switching, which I use all the time).
For me, the one huge advance the HX line has over everything else is Helix Native - but that's not hardware related and apparently it's not all that important for other folks.
Others than that, unless you really need something very close to the very exact feature set of the Helix, the competition has gotten extremely tight.
And yes, I absolutely liked my Helix Floor and possibly like my HX Stomp even more, but the next Line 6 modeling generation needed to offer quite something or come at a very competitive price.