Go take a look at any cycling forum that has a large quantity of road bikers and you’ll see lots of discussion about the weight of part X or vs the weight of part Y. You may even find some people trying to figure out which hub has the least rolling resistance so that they can improve their personal best time on X route.
The reality is that neither part X or Y will make you go faster. The rolling resistance of your hubs will not help you be first in your local group ride town line sprint, so give up on the discussion of which parts will make you a better cyclist.
I ultimately believe that this comes down to the desire for instant gratification. The cyclist wants to find an easy way to get faster. The secret is that the best way to get faster is to train harder and smarter. Parts won’t do it really. Sure a TT bike puts you in a more aerodynamic position, but we’re talking about the pedals on that bike hear.
So here’s a call to cyclists, don’t worry about what part is the lightest, or what pedal offers the least rolling resistance. Get out there and start training harder and smarter. Anyway most of us could loose the few grams of difference between parts with a short hair cut.