It depends on the species... Ball pythons are VERY different in that they PREFER small homes.. Here is why.

In the wild they live in either termite mounds, or abandoned/stolen rodent burrows. They spend most of their life in this mound or hole and rarely come out.. Males have been observed hunting, and even being in the low branches of trees at time. They also travel looking for females burrows during breeding season. Females will often stay in their home indefinitely as long as enough food happens by the entrance. They have no want or need to go anywhere.

The species is a solitary, terrestrial, nocturnal, and very timid snake. They often stay coiled in their "ball", and prefer to be touching the sides of their enclosure, hide, or in the wild, their mound or burrow. Or buried under something like bedding, newspaper, whatever.

It is simply a fact which is known through years of keepers noting their animals behaviors and habits. Especially those of hatchlings. They simply do better, eat better, etc, in a smaller enclosure. A larger enclosure can be heavily cluttered up to fill all the extra space with tight hides, crumpled paper, etc.. Really though, the proper sized cage is always better.

We're not talking about a boa or Retic. BPs are naturally nervous and want to remain enclosed and hidden. Sometimes you end up with one that couldn't care less either way, but it certainly does not require the extra room like some other species do.