As I have done during many preschool shows I have to wonder what the backstory is. For example Pigs lack opposable thumbs and yet in the cartoon can drive cars clearly made for human ergonomics.

I would posit that Peppa Pig is actually a sequel to Animal Farm. Humans destroyed the environment and became extinct by a combination of global flooding (everyone in PP lives at the top of a hill) and animal genocide.

The animals then evolved consciousness and created a civilisation built on the remnants of the human world.