The question is, who benefits from a house with 118 people living in it?

The answer is the various local businesses, hospitals, etc. Instead of having 5 or 6 people (prospective customers) living in the house they have 118 prospective customers that they can profit from. This works out to a 2000% increase (yes, 2K) in prospective customers as compared to the US average of 5.5 people per single family dwelling.
Many businesses have illegals on both sides of the counter (illegal employees and customers) which drives their profit margins even higher.