"That's due to a lack of investment by governments to support those families."

Please show the evidence for this being true. Birthrates are low even in countries that provide a lot of support.

No country provides a lot of support. Some countries provide more but inevitably if you poll people they’ll mention that they mention significant financial deterrents, not to mention things like climate change, all of which are valid. People only need one of them to be true to decide to have fewer children, while society needs to help address all of them.

For example, if your government provides housing and childcare support—and say that’s the unicorn where those are consistently available, high quality, and cover the full cost—but still culturally tends to mommy-track careers into dead ends, despite doing those other things well you are going to have a lot of women decide not to risk multiple decades of lifetime earnings.

"No country provides a lot of support."

The evidence suggests this is not true. The rest of your comment points to non-financial issues.

https://www.newsweek.com/norway-birth-rate-fertility-rate-pa...

Yes, support does not have to be financial. If you read the entire article you posted note the experts quoted made the same point: opportunity cost is real. Career impact is real. The shift to getting educated and established in a career is real.

Societies have to address many different sources of no because the only reason rates used to be higher in the past was women not having a choice.