If you think about race cars, there are different kinds of cars for different purposes. Some are made to go as fast as possible in a straight line and some are made to corner at 200 mph. The ones that are optimized for straight-line speed can't even turn and the ones that corner like they are on rails have so much downforce they sacrifice straight line speed.

In bikes, you have similar concepts... TT bikes that are optimized for speed sacrifice comfort and handling. Bikes that are made to be stiff for sprinting are often heavy and bikes that are optimized for weight are usually not as aerodynamic. It's all tradeoffs, and races are not usually won by TT'ing away from everyone.