It's not killing off the middle aged, there's just deaths attributed to covid. The CDC tables record PIC deaths and report that total as covid deaths... PIC is 3 illnesses, pneumonia influenza and coronavirus. The younger being reported as covid deaths (for under 55, more suicides annually than total deaths reported as covid) are just the flu deaths.

It's less bad than the flu because influenza, pretty much any of them, will kill children and young healthy people (like every flu season that nobody paid attention to)