Some years ago (about 30) I watched a television show of former science advisers to the president of the United States.
They were asked what problems the U.S. faced in the future. Four or five of the dozen or so said it was “depopulation.” Since then I have told others of this, but few (if any) have believed me. Now I would say “depopulation and aging populations” are a problem. How much? I do not know. But certainly, something to think about.
Some of what we know is not always true.