For every 3 employed Americans, 2 adults are outside the labor force entirely. Most people picture "not working" as unemployment, but the unemployed (7.1M) are a rounding error next to the 105.8M who aren't looking at all.
Over half (48.6M) are retired, and the 45-year climb from 60.8M to 105.8M is largely the Baby Boomer wave aging into retirement plus population growth.
The NILF share of adults rose from ~36% (1980) to ~38.5% (2026), so it's mostly population and aging, with a modest real decline in participation. #education source