Does that sound sustainable in a world of low or no growth with total fertility rates rapidly declining?

https://www.mckinsey.com/mgi/our-research/dependency-and-dep...

https://www.cato.org/cato-journal/spring/summer-2018/demogra...

https://www.cato.org/cato-journal/spring/summer-2018/demogra...

https://ourworldindata.org/grapher/children-born-per-woman