I was once a critic of "all that aero crap". Years ago I did a training ride with a buddy on a 1-mile flat loop. We swapped pulling at each lap. At the time, we were dead even in fitness. He showed up on a TT bike, aero helmet. I laughed... briefly. I had to work to stay on his wheel. I heard lots of freewheel on my pulls. Eventually, he rode me off his wheel. Science hurts.