Worth adding that “unemployment” in this context just means people who are claiming unemployment benefits, a things that runs out, and when they run out, they no longer are counted by it.
Also difficult to claim unemployment if you lose a gig economy job. So many people who lost their “job” doing something like uber eats are not represented.
A better metric is workforce participation rate which is at an all time low. There are a lot of factors to that, including a higher rate of retirement, but that alone does not account for the record low number.