I wish there was a way for us to process immigrants more quickly in order to allow more of them into the country. That would take care of the "replacement" problem due to low birth rates.

In additional to chemical reasons for infertility, we also have availability of abortions (or at least we did until Roe was overturned), we have an increase in people identifying as transgender (girls identifying as trans have shot up by 4,000 percent in the past few years), and people who opt not to have children because of how the perceive the state of the world to be.

Maybe some of those reasons will also play more into future infertility rates and be all the more reason to be more open to immigrants.