The innovation that has really benefitted the average rider is index shifting, especially being able to shift while keeping your hands on the handlebar. Partnered with shifting aids, it takes the lowest level of skill to operate.
I remember when Shimano came out with SIS. One of the negative aspects for professional riders was the loud click of the DA 7400 shifters. I had a set of 7401 shifters and they were so loud on a quiet route you could probably hear the click for an eighth of a mile. No sneaking up with those.
But my younger self did enjoy those times of trying catching up to someone knowing those shift clicks were heard coming up… lol.
John