Most animals are just trying to conserve enough energy until their next meal since they haven’t invented grocery stores yet. If that means they sleep between meals than that’s what happens. Predators get that luxury. Prey animals sleeping all day is probably a bad idea.

Humans are also an outlier when it comes to energy conservation. Our bodies are ridiculously efficient but at the expense of not being very strong or fast. Endurance hunting is a thing humans can do. Instead of running faster than our prey we run longer than they can.