I agree it looks bleak but I have to challenge you on the 4.5% mortaility claim. That is unrealistic. That is probably based on how many are tested. But to get the actual mortality rate you have to do anti-body tests or test T-cells as far as I know.
That can give you an estimte of how many in the population got infected and allow you to estimate mortaility rate. From what we know from various countries the mortality rate of COVID-19 is likely around 0.6% to 1%. That is bad, but not as bad as 4.5%.
But you forget another important number which is the number of people who get seriously ill and who get permanent health damange. We cannot forget to add that to the calculation.
It is a small comfort that you don't die if the whole rest of your life is destroyed due to terrible health conditions you have to live with for the rest of your life. This affects quite a lot of young people as well.
And finally let us not compare COVID19 and the flu purely on mortality rate. A lot of people have resistence towards the flu so it does not spread as fast or to as many people. COVID19 spreads faster and to more people because few if anyone has any resitance to it. It is a new virus after all.