... a recession worse than the Great Depression is looming. How accurate is that?

Depends on the reaction by the authorities. All indications are the governments will intervene, creating a floor on prices (though exactly where is unknowable). If not, at least everything will be much, much cheaper, but that really gets into the hypothetical.

About 1 year or so into the Great Depression, the laissez-faire Hoover administration was forced politically to start fiscal stimulus if that’s any indication. Stocks eventually recovered. A long term investor should use stocks for money needed/wanted decades later, allowing savings growth, along maybe a little bit of reinvested dividends over time. When needing the money usually to retire or for a kids college tuition, start cashing out a number of years ahead of that target date as stocks are volatile. If wanting it for a luxury, such as a vacation, I’d argue wait until a year or 2 ahead.