That's mostly true! But it does matter how many children Jose has. It matters if he can't support them and requires others to support them for him. Supply and demand works in all things, not just goods and services. Supply and demand works with wages and homes and savings and yes, population. It's a law of the universe, it applies to humans the same as it applies to the animal kingdom. Overpopulation of any species is a death sentence to many and a threat of extinction for the entire species.

When people live and reproduce within their means, everyone both survives and prospers. When people live and reproduce beyond their means, people die and everyone suffers.