> they are largely choosing to have less children

If the suicide rate rapidly increases, will you also say they are largely choosing to have less life?

Nothing to see here, just choices.

> So by definition, given it's a choice - women are happier.

So by definition, given it's a choice, people who commit suicide are happier.

Hmm - childlessness ( note this is different from reduced family size ), almost doubled for women in China between 2010 and 2020, and over a similar period the female suicide rate has halved.

How do you explain that?

Sure having children is still a protective factor, but the highest risk is amongst those that wanted children but couldn't, rather than those that choose.