I think it has a lot to do with the birth rate. Here's a study from the prior century on the topic - there are a lot of correlated "people doing well" metrics,

I think it has a lot to do with the birth rate. Here's a study from the prior century on the topic - there are a lot of correlated "people doing well" metrics, but when they controlled for fertility only it had the strongest negative correlation with suicide. https://pubmed.ncbi.nlm.nih.gov/1737819/ https://pubmed.ncbi.nlm.nih.gov/1737819/