I used to take these with a grain of salt indeed, but this is a meta study that finds effects that seem consistent.

I think that happiness probably includes meaning for a lot of people and furthermore it’s a hard sell telling them that they shouldn’t want to be happy.

I’d also turn around the statement about parents who wish they hadn’t had kids (though I did at one point accidentally date a woman who was married with children who clearly didn’t want any of that) to say that I also suspect that those who avoided having children on purpose also rarely regret that decision; some people are just different ultimately I suppose.