You must mean index shifting (not "click shifting"), the use of carbon fiber is by far more important than disc brakes and so is lycra with synthetic chamois.
IMHO, it's still lighting. Huge improvements.
I was pondering the real value of indexed shifting some time ago ... I actually think the primary advantage isn't so much the ease in shifting ... it's the fact that you can have 10 and 11 speed cassettes. Hard to do when you are friction shifting.
Speaking of which, the move from clusters to cassettes some time ago was a significant advance, IMHO.