According to BLS, 141k workers earned exactly minimum wage in 2022, with another 882k earning a base rate under minimum wage [0]. The latter category, though, isn't the complete picture, because tips and commissions would tend to push compensation up over minimum wage as a rule.
Of the 141k, 53k are teenagers, so that leaves 88k full adults (age 20+) making minimum wage. That's not nothing, but it represents 0.1% of those paid an hourly rate and 0.06% of the workforce as a whole.
[0] https://www.bls.gov/opub/reports/minimum-wage/2022/home.htm
