friction shifting works better with the wider spacing of 5 & 6 speed rear cog clusters,

then the shifting is a skill , the rider learned , late , over-shifting,
then re centering the pulley under the cog.. each time..

engineers took over, now there is a early shifting and no real need to be that involved.
klick the lever, and , as long as the front end of the lever, and the stuff in back
are remaining synchronized, the shifting goes OK,

Count the number of pages of questions on this site alone,
of the problems people have when the shifting does not go well.

then the reason/fix analysis, gets more complicated,
as the mechanism becomes more complex.