Originally Posted by
noodle soup
when you decrease the cable pull, there’s less room for error(cable stretch/housing shrinkage).
JMO, but frequent replacement of very inexpensive part, is a fair trade off for smooth and light effort shifting. I suspect that is why Shimano hasn’t redesigned the shifter.
Maybe I wasn't clear - it's possible to increase the diameter on the cable spool without increasing cable pull or shift effort. It's even possible to retain the same lever throw, at the cost of a few grams for a roller and cam or something.
But I seem to recall Shimano's marketing bragging about reduced lever throw, so hey, twofer.