Is it all private sector jobs? Which if so is extremely weighted down by tons of minimum wage jobs. While I’m sure there are plenty of mail clerks in Government most jobs require a bigger skill set than your private sector minimum wage jobs.
There is definitely a kernel of truth here.
Over time the lower pay hands on jobs in maintenance and mail delivery, landscaping/mowing, operations of systems etc have been contracted out to give the appearance of reducing the government budget.
Thus those lower paid jobs are no longer in the government sector thereby in effect leaving only the higher paid functions to skew the average wage upward.