The bolded is wrong.
I'm no expert in any of this, but just poking around on the internet, it looks like about 15.3% of COVID deaths are in the 50-64 age group. At 318,000 total deaths in the US so far, that's about 49,000 deaths in the 50-64 age group.
https://www.aarp.org/health/conditions-treatments/info-2020/coronavirus-deaths-older-adults.html
The University of Washington is predicting 561,000 deaths in the US by April 1. That would be about 555,000 deaths from April 1, 2020 to April 1, 2021, about 86,000 of which would be in the 50-64 age group if we stick with the 15.3% figure.
https://covid19.healthdata.org/united-states-of-america?view=total-deaths&tab=trend
There are about 6,000 deaths per year in the US attributed to the flu in the 50-64 age group.
https://www.cdc.gov/flu/about/burden/2017-2018.htm
So, COVID is about 14x more deadly than the average seasonal flu for the 50-64 age group.