So... how are things going to "have to change" if you can't threaten childless couples and you can't redistribute the wealth to people that do want kids? Continually fearmonger mandatory birthing policies without actually implementing them just to get a rise out of your citizens? It's nonsense, and if America is given a choice between "fucking over wealthy people" and "having tons of kids to staff McDonalds at minimum wage" I can tell you offhand which one 99% of citizens will pick. We're already halfway there given how far China has surpassed the US in places - today's Americans hate capitalism so much they're content watching their country suffer until businesses get the message.
More then this - public pensions are one of the main reasons for low birth rate. You can't have both, if children's role as social insurance passes to public pensions - children became useless.