....Given how contagious it is, I would assume more people would have it by now.
Much of this depends on how prevalent the virus is in the community, and community compliance with the mask, wash hands, distance, limit trips out thing. If your essential worker folks are doing their part to keep themselves safe, they may either be effective at that, or virus not that prevalent in their community, or not that prevalent at their job or job is doing a great job on protecting their people.
honestly, I think some of it is a crapshoot. We can't see it, we can have it and not know it...
I'm glad your essential worker friends/family are healthy!