But we can regrow them. We just evolved an anti-teeth-regrowth substance/molecule that's in our blood and shuts down teeth growth once adult teeth are finished, because adult teeth roots are so deep that they require surgery to pull the old teeth out to make space for new. Also historically humans didn't live that long, compared to the decade it takes adult teeth to grow.

They're doing phase 2 trials in Japan right now, on children with a birth defect that blocked some teeth from spawning.

The medicine is a monoclonal antibody "antiserum" that neutralizes the teeth-growth-blocker.