Not only the widths, but the curves, bends, and drop height too have changed. A lot of folks enjoy the "anatomical" geometries and wider bars. Like many of us, I rode 38's forever, never knowing there was an option (because, in all practicality, there wasn't!) My early Cinelli bars were wider and I didn't realize at the time that was what I enjoyed about them... I just knew that I liked them better than any others I'd had up to that time. Later, when the Cinelli bars became available in still wider configurations, and then other bars started to pop up similarly so, I found I could experiment and find my ideal width. I now enjoy riding 44s on classic road bar geometry, and 48s on the VO rando bar geometry (effectively measures about 44 on the tops, 48 on the drops due to the slant.) I still have my original Cinelli bars, by the way, and they still feel good to me. Narrow French bars, however, look great on the bikes but I seldom ride them for lengthy miles.