The problem with these things is that the decline only becomes obvious 2 generations later. At that point, even with acute turnarounds and higher birthrates it will be probably 3 generations to get it back to previous states. The only immediate solution is immigration which has its own set of problems which also take several generations to settle.

I can perfectly understand people do not want to have kids because in this day and age it's really hard to make a decent living. Having food on the table and paying a mortgage already takes 2 in most cases to make it comfortable and adding kids to this might make it too hard for most people, but in the end they will still suffer because there will be nobody there for them once they grow old.