I did not read all 7 pages of this thread, so I am likely repeating someone by pointing out that we do not have more gears now than we did 20 years ago.
More cogs, fewer rings, fewer gear combos.
btw, I am not aware of any tests that indicate that chain life has on the whole decreased with more gears in the back. But they have gotten more expensive.
Last edited by Kapusta; 11-19-21 at 06:02 PM.