People need to give up on the idea that the replacement rate needs to be met all the time, everywhere.
It is ok, and natural for populations to decrease intermittently.
We have too many people. We can’t find affordable homes for the people we do have. We can’t meet the energy demands of the people today, without borrowing from the well-being of our planet’s future.
People are correctly looking around at the world and deciding they don’t need to be bringing more people into this world as it currently stands.