Labour market is tight because after covid people are not willing to work at many jobs at the peanuts they were paid for before nor are they willing to change the work life balance they would need to sacrifice for these jobs.

there's that plus i think a bunch of boomers (like my parents) took it as a sign to retire.

And also nearly a million people died in the US. Even though most of those were elderly and probably not working, it's not insignificant.

https://www.worldometers.info/coronavirus/country/us/

3 million babies were born each year, but they're not contributing to the labor market.