Because in prehistoric humanity, without the knowledge of toothcare or ease of access to scrubbing agents, your teeth would rot out in old age(about 20), but then the wisdom teeth would grow in, and you might barely live long enough to be a withered old husk and maybe see your grandkids born(about 30). The before times were rough.
Wisdom teeth were amazing to have back when dental care didn’t exist and our teeth fell out from decay or injuries.
Why?
Because in prehistoric humanity, without the knowledge of toothcare or ease of access to scrubbing agents, your teeth would rot out in old age(about 20), but then the wisdom teeth would grow in, and you might barely live long enough to be a withered old husk and maybe see your grandkids born(about 30). The before times were rough.