Small bars counter point.

I have the 3T Scatto bars that I think are 35 cm that I use on the track primarily for team sprint. These became popular when it was discovered that they were worth about .1 seconds in a flying 200 meters versus standard width bars.

However, the narrower width reduces leverage on the standing start. I suspect for road sprinters, leverage may be a big deal when the sprint is launched depending on how strong one is in the upper body and how much one throws the bike.

Also, bars that are narrower than the shoulders change the angle of the arms in the shoulder sockets. This may or may not be a problem.

I had narrower bars on my road bike and went back to wider bars for comfort. I have broad shoulders.

So like most aspects of cycling, IMO, bar width is a big depends and will require a period of time for S&A to take place before there are benefits.