RE:In the 1930's apparently the majority didn't realise ....Dear Lord, you are a pessimist, Ardbegoil. Unfortunately, I can't say you are wrong.
Right now the problem is that the market seems to be in denial. Overall, the market has not come to terms with either the facts of COVID or the uncertainty it has created. I think you are right about the crunch coming on mortgage and loan deferrals. A lot of people are going to find they have too much debt and that will lead to a sell off in the real estate market (forced or unforced, the result will be the same.) There will also be a lot of people without work or the prospect of work.
The overall stock market will drop and drop hard. Maybe over the summer, almost certainly in the fall. The only sector I can see doing well is that tiny sliver of PM explorers, developers and producers. For no other reason than they are literally "mining money".