Check your premise.
The appendix has a use.
It is a reservoir for friendly intestinal bacteria to to repopulate your gut after a bout of "stomach flu".
Mine went over to the dark side and had to be evicted...
That was exactly my point. Our "brilliant" doctors decided we had evolved beyond it because they couldn't figure out a use. They yanked them (tonsils too) because they didn't know they were useful. Then, "Oops, we figured it out."
We've been far too arrogant in thinking we knew about the body.
(Asimov actually wrote a story of a future in which men didn't have appendixes - er - appendices - er appendixii - er whatever.) Foolish evolution theory strikes again.