Zhejiang Dingyuan Pet Products Co., Ltd tells you the benefits of buying a cat house:

Cats like to sleep in places with their own smell, so that they feel safe. If the cat gets used to the bed, it will recognize the owner's bed.
Therefore, if the cat is allowed to sleep in its own litter from the beginning, then the cat will look for its own house. Although it will sleep in other places out of curiosity, it will still "take its nest as its home".
In hot weather, you can buy a corrugated paper nest for your cat, which can be used as a cat scratcher and can sleep.
It is best to buy a cave-like nest in winter, because the ancestors of cats were cave-dwelling animals. Only when they live in a nest with small openings and dark light, can cats feel safe.