> The problem is that I have been seeing some version of the “crash imminent, sell everything” thesis for my entire life.

What do you think is the root cause for this kind of thinking? It is hard-wired from childhood, or borne of (difficult) experiences?

    > Much better to just stay in the market, knowing that there will be crashes and you will have days where the numbers look awful, because they’ll look great again in a few years.

This assumes that you are talking about the US stock market. Most other stock markets are far slower to recover from economic downturns and crises. Why? Their economies are less dynamic and their political leaders are more fearful of difficult (economic policy) changes.

    > The stock market is a mechanism for transferring wealth from the impatient to the patient - Warren Buffett

    > For 240 years it's been a terrible mistake to bet against America - Warren Buffett

Lastly: The Nikkei 225 (Japan's most important equity index) peaked in 1990, then took 30+ years to recover.

Also: Look at Mainland China since it was opened to (direct) foreign investment in the last 15 years. Overall: The Mainland China economy has grown a lot, but their stock market is a terrible place to invest.