I'm surprised that the young people who grew up around economic recessions (including one right now), record student loan debt, a lack of affordable housing, school-shooting drills, a global pandemic, a rapidly-declining environment and (at least in 2020) President Trump wouldn't have the funds or faith to have as many children as previous generations.
I agree with some of the economic factors as well as Covid but I doubt school shooters play a big risk into decisions on whether to have kids or not. Murder rates were far higher 50-30 years ago.