1 in 17 hospitalizations will end in death. That means that for every 17,000 flu cases, 1 person dies. We would expect fewer than 20 deaths from COVID-19 at this point if it was just a “mild flu.”
Now certainly there are more people infected than we’ve confirmed. With 12,000 deaths at this point, we would expect to see 204,000,000 infections if it were on par with the flu. Many more if it were a “mild flu”. Do you think there are over 200,000,000 cases right now?
So yes, many people don’t have symptoms. And for many people who do have symptoms, this is obviously much worse than a “mild flu”.