A solid majority of countries are still experiencing population growth, and among those shrinking, the magnitude is small - the largest population decrease (in a non tiny island nation) is in Latvia, which is shrinking around 1% a year. Hardly a collapse.

https://en.wikipedia.org/wiki/List_of_countries_by_populatio...

I think the rate of change is pretty slow right now but number of births per woman has gone down. If these lower levels stay or goes down further then the population will start to shrink faster in many countries. Some countries may be able to delay this by taking in more immigrants.