Neither am I. But, the problems that are, and will be created by falling birth rates and a smaller population overall, are real too. That can't be denied.
Now, are they unsurmountable? No. Should they be talked about? Yes. Locally, the high/middle school was over built just a few years ago. It's already clear it's far bigger than we need now, or are likely to need for many, many, many years - maybe ever. (Our 'average class' size has fallen from ~200 to barely 120-30, at best... In just a few years. With no signs of ever improving.)
When does it end, though? How many human beings can this earth support? At what cost of natural resources, flora/fauna, environmental harm?
AI is increasingly taking over jobs that previously required humans. How many humans are actually needed to support current populations? How many of these now-displaced humans will enjoy enough resources to sustain themselves while increasing humanity's knowledge base, artistic pursuits and general intellectual/emotional enlightenment?
These are not rhetorical questions. I don't know the answer to these things. It seems to me that increased population for the sake of population growth itself is not correct.