Sports chassis and similar units becoming obsolete?

I think they'll make a come-back soon.

Biggest detractor is lack of a good 4x4 option. Any true MDT with 4x4 is too high for towing most 5th wheels.

Once somebody offers a series-hydrid powertain, front electric motors will make 4x4 (or really AWD, but in some ways this can perform better) feasible without raising the chassis-height.

Articulated transit buses already offer a similar powertrain. Diesel gens-set is mounted at the back. Rear and center axles are electric-powered.