i think this needs to be analyzed per gender. Because 2 curves are very different.

Female participation rates have been rising historically and it's completely recovered to pre-2008 levels https://fred.stlouisfed.org/series/LREM25FEUSM156N

Whereas, male participation rates are declining and did not recovered completely yet. https://fred.stlouisfed.org/series/LREM25MAUSM156N