" It is impossible for 80% of Americans to receive something from their employer if 80% of Americans didn't even have an employer."
Data aside, that is not a logically true claim: in 1980, I had health insurance... through my mother's employer.
Data aside, that is not a logically true claim: in 1980, I had health insurance... through my mother's employer.
Also of note is that when you do calculate in Spouses and children, they still had insurance because it was less common to "only insure yourself" (I have no data to back that statement up).
But yes, I suppose that on some level you're right: 80% of the population has probably never been simultaneously employed.
Nor will that ever be the case.