100% of the population was not "penetrated" with the flu between February 1 and now. Evidence implies a similar proportion of the population was "penetrated" with COVID-19 and the flu in that time. This implies a similar death rate for COVID-19 and influenza in those age groups, as the poster said.

Indeed, influenza has been greatly impacted by distancing. The surveillance numbers for influenza are lower than you'll ever see for this time of year.

I can't exclude it's twice as bad as the flu (or half as bad). But even those broadly agree with the poster's statement.