Might the elevated level of the stock market not also be a factor of people trying to pick the winners and being (as always) bad on the whole at it, thus resulting in an overall increase ?

Let’s say covid-19 hits, I’m an idiot but a lucky idiot and once I see the market drop a few %s I pull everything. Once I see a 30% dip I might think “Hmh, well, some European low cost airlines will bite the dust, but some will come out ahead with less competition, so let me tentatively put like 5% of that money on the one I think ought to do best, since after the pandemic is done with the added cash influx from the governments it will peak even higher than before”… and if everyone has that mentality for certain sectors, and everyone is on average bad at picking the winners and losers, what you’d observe (I guess) is around the board increases in stock price.

Which I’d guess would have been less of “a thing” in the last recession since the effects were much more generalized, in this one, at least on the face of it, it seems like you could find obvious winners and losers once the world accepts covid-19 as the new normal (and/or a vaccine is developed)… not saying that’s the case, since at the end of the day everything is interconnected, but it does explain a scenario that includes both “investors thinking this is very serious” and “stock going up overall” where those two things don’t contradict each other.