My touring bikes and rando bike are all at 44cm (center to center), my road bike is 43cm. I was curious so I measured them, I had bought the bars so long ago I could not recall what they were except the road bike that I bought as a complete bike. I am 6 foot in height.
Tops of my bars are about the same height as the top of my saddle. I am not a racer, aerodynamics not that critical to me.
My touring bikes with that width have seen plenty of gravel with panniers, front and rear. That width was adequate for me for leverage on rougher terrain with panniers. My bars are regular drop bars, not the cowchipper style.
If you are contemplating a bag on the handlebars, make sure you have the clearance you need. In the photo, I have the room I need but if my bag was higher the pocket on it would interfere with shifting. The bag in the photo is the biggest handlebar bag I have, I use that for touring. I have my bag mounted lower on a second stem which lowers my bag. This photo is on my rando bike when I built it up seven years ago, I was checking for clearance so used the widest bag I had when I checked for clearance.
