The problem wasn't so much 3D itself as much as it was texture mapped 3D, both of which struggled with that (the Jaguar less so than the 32X in that regard). Unfortunately, non-texture mapped 3D was dated pretty quickly, on one hand thanks to the 3DO that was already on the market, but especially once the PS1 and Saturn dropped. The flat (32X) or Gouraud (Jaguar) shaded polygons weren't going to cut it then.
As far as what a Mortal Kombat would have looked like on the Jaguar, all you have to do is take a look at Kasumi Ninja. As poor of a game as it is, it at least features the same kind of large digitized sprites, smooth framerate, high color count and the same scrolling floor effect. Had MKII in particular been commissioned, it's possible it may have been one of the better conversions at the time.
Most of the textured mapped games on 3DO were pseudo 3D or 2.5D, combining texture mapped polygons with sprites. Crash n Burn had less interaction than both F Zero and Mario Kart on the SNES. It plays very limited. Same with Road Rash, terribly overrated game. Complex 3D with full fledged sim games was in most cases not fully texture mapped, even on PC. Jaguar was probably better than both 3DO and 32x, I could imagine ports of PC sims on it, but the Playstation really all made them obsolete.