> This ascribes an agency to capitalism that doesn’t exist.

Oh no, it really doesn't.

Captialism is everyone working to maximize profit. It's the lack of foresight on social problems and pressures in capitalism that leads to exactly this problem.

> The families themselves make the choices to have more or fewer children.

Right, because of the pressure of a capitalist society. People can be priced out of having children if necessities like food, housing, and clothing price them out of being able to take care of a child.

> Capitalism says nothing about free time.

Capitalism is about maximizing profit. A direct path towards that is paying employees the minimal amount and having them work the most hours to extract the maximum amount of value from them.

Before mass unionization, 60 or 80 hour workweeks were pretty common in the US. Even today, we see companies that use salaried employees as a way to make employees work longer hours.

If overtime wasn't so expensive, you could bet that McDonalds would have people working 12 hour shifts. Hospitals already do that to nurses.