This is incredible. Not only do you start with an "upper bound" less than one-half the accepted value, you then toss in a "3-4 order of magnitude" reduction, which is so fantastically impossible that there has clearly been zero actual thought. Just rhetoric. Elon Musk, is that you?
Actual medial professionals are seeing that even tiny spread in a community the healthcare system becomes absolutely overwhelmed. Hence all of the emergency declarations. The Internet intelligentsia would like us all to believe that millions are walking around with it, and the fact that you can trace individual branches and the horrifying results is just a remarkable coincidence happening throughout the globe.
No, this isn't the plague. At the same time anyone who seriously compares this virus to the cold has started in a completely broken, intellectually dishonest and dangerous place. Add that to the silly claims about death rates...
As to investment opportunities, this is an incredibly lazy, zero-value observation -- yes, in the future the market will grow. Nobody thinks otherwise. But right now the market has lost some 35% off a frothy, already-in-danger high, and ahead of us are heroic government responses and a lot of economic disruption. But yeah, at some point it's going to hit bottom, and if someone is willing to churn on limited returns for a while it'll eventually pay off. You could say that in every downturn throughout history.