The kitchen is a place where the fire is big and the water vapor condenses. Generally, it is advisable to fill the kitchen with solid soil. The cement floor prevents the infiltration and resurgence of water vapor to a certain extent, and destroys the water-fire balance. Unless the ventilation is particularly good, such a kitchen will become a place where luck gathers for a long time, which is not good for food and the health of the host family.
The solution, of course, is to improve ventilation.