Smallwheelers DO have enough potential to be as fast as top road bikes (given the road is smooth enough), but they are SERIOUSLY outdated - Modern road bikes have both featherweight AND aerodynamic carbon fiber frames & wheels.
Nowadays sub-kg frames are common, and you can build a very light roadbike quite easily. I have built a 13.2lbs one for my dad, and most people around myself are now riding ~15lbs machines. Have you seen ANY light and stiff framekit options for smallwheelers? I haven't seen anyone except for Tyrell scandium frame which costs more than most carbon road frames.
And for aerodynamics... nowadays deep section carbon wheels are very common, and developers are throwing a lot of money for windtunnel testing and improving them. Aerodynamic frames with wind-foiled cross section are also popular. How can one claim that smallwheeler are more aerodynamic, even without a single windtunnel test?