Some fancier models use cameras for obstacle detection and avoidance. They try to identify stuff than chokes and clogs the robovacs so they can avoid them, like socks, USB cables or Lego on the floor, or my personal favorite, pet poop.

There was a funny video on social media, of a home surveillance camera capturing the pet taking a dump in the middle of the living room, and then the Roomba smearing it everywhere as it did its rounds. If you're a pet owner who's companion can do their business in your house, having the robovac smear it everywhere is a nightmare you'd want to avoid at all cost, and that can only be solved using cameras.