Elder millennial here. I had kids, my brother didn’t, and my kids, though young enough to change their minds, are adamant they won’t have kids.
I think the more interesting stat likely unfolding is the marked decrease of great grandparents in a generation.
To be clear this is not a “threat to society” or whatever, people can decide if they want kids or not. Just a shower thought.
I suddenly developed a theory that GPT and the like are popular because people don’t know how to craft a google (the noun not the company) search.