Bars have changed in a lot of ways since the 80s. The big change was Ergo / Brifters / SIS people ride in one position more with hands on hoods. This means a shorter reach for the bars. With a shorter reach and your arms staying the same length you can spread them wider for comfort.

Among the racers the mode has been to have the tops lower than before with the drops at the same height relative to ground, or rider, so a shallower drop.

The pros are skinnier with less upper body strength than ever and need more leverage.