> The recent proliferation of studies examining cross-national variation in the association between parenthood and happiness reveal accumulating evidence of lower levels of happiness among parents than nonparents in most advanced industrialized societies.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5222535/

I never saw myself as capable of withstanding the stress of parenting and so I never even really thought about having kids. I thought I was a far outlier, but, given trends in fertility, I think I may have just been early in realizing this.