I don't see how. We already live long enough to have a dozen kids per family. It's just that our society is structured such that raising kids is an expensive nightmare.
It’s not just about money, the enjoyment/benefits of having a child decreases dramatically with each child you have. Having more than 1/2 children is really tough on, particularly on the mother, both physically and mentally. If you have the choice most people will not opt for more than 2 or 3.
I heard the opposite, directly from people who have a lot of kids (one person I know has 13): it doesn't matter all that much in terms of labor how many you have if you have 3 or more. The first one is a lot of work, after that the increase is marginal. They begin to take care of each other more, which I think you will agree is a desirable thing for any human to learn early on. It's _slightly_ easier in terms of _marginal_ cost, too (younger kids can re-use clothing, toys, etc), but only marginal, the cost largely goes up linearly due to the impacts of daycare, tutoring, extracurriculars, and higher education, all of which are expensive AF in the US.