im p sure it has to do with stuff being easier to eat. we dont have to work with our jaw to tear or crush difficult foods since everything is processed or we have tools to make it easy. our jaws are underused, so they develop to be smaller than theyre supposed to be, and our teeth get crowded

Before we cut our food in perfectly sized bites with utensils our ancestors used to do it by biting into large pieces of food with their front teeth. That would wear them down evenly to form a nice flat bite.

I wouldn't be surprised if that's the skeleton of someone who died way younger than we think as well.

Everyone who's replied to you so far are wrong and speculating. The real issue is actually lack of nutrition and exercise for the mouth. We're not growing our jaws out quite right while our teeth are coming in.

We eat shitty food

Sugar content of our food is one of the reasons I read before as well.

Our food is way softer so we don't chew enough to maximise the growth of our maxillae and jaws.

because people with very bad teeth survive nowadays

I think I’d read before that it was because most of our foods now are soft foods so our teeth/jaws are not as strong.