Coronavirus and the seasonal flu are not equal. I think this is one of the better
visualizations of this. Although the deaths seem the same, the coronavirus "season" has just begun while the flu season has been going on for months. This dramatic increase in deaths has occurred despite the quarantines in place all over the world.
Like other viruses that recently jumped from another animal to humans (e.g. SARS, MERS, HIV, Ebola, etc.), the coronavirus has a high mortality rate, ~1-3% according to most sources (e.g.
this), this is in comparison to the 0.1% for the seasonal flu, meaning COVID-19 is about 10-30 times more lethal than the seasonal flu. This is subject to testing biases, but the consensus is that the coronavirus is significantly more lethal than the seasonal flu. It's also thought that the Coronavirus is more infectious than the seasonal flu with each infected person infecting about 2-2.5 others on average. For the flu, this number is about 1.3 (
source). In addition, the SARS-COV-2 has a longer incubation period than the flu (average 5 days vs. 2 days for the flu), meaning people are infectious without symptoms for a longer period of time with the coronavirus than with the flu. Overall, COVID-19 is about twice as infectious and 10 times more lethal than the seasonal flu.
Finally, and most importantly, the coronavirus has an extremely high hospitalization rate per case (subject to testing biases). About 20% of cases or more require hospitalization in comparison to the ~1% for the flu (
coronavirus source,
flu source). The lethality of the disease would be higher without medical intervention, and the disease puts much more stress on the medical system than the flu. For example, had Boris Johnson received no medical support he may have died.
This is the point about locking everything down, we need to limit the case load at any given moment because if the healthcare system gets overrun, the coronavirus situation will take a catastrophically lethal turn.
Of course, we will have to break quarantine eventually, and, ultimately, a large percentage of the population may get the coronavirus. We just need to be sure that our healthcare systems can handle the load at any given time. This is the idea behind "flattening the curve", and this decision should be left to qualified experts. Perhaps this time is coming soon (in the US at least). It sounds like the pressure on the medical system has been alleviated as of late. I wouldn't be surprised if in a week or so things are opened back up, especially considering the political situation in the US.