If everyone knows the equity markets will enter a bear market at some point, what is the reward from here that makes the person “risk on?”

The risk is not arbitrary or random. Like the average S&P return, the risk is historical facts.

The featured underwater performance chart is based on buy and hold from mid-1970. 100% passive DJI average. I kicked out the post WWI baby boom and the 1930-1940 bust for a proper point of view given that everyone looks at data from 1950 to date, which is biased as well as incorrect today.

Because today post WWII baby boomers do not influence today in their avoidance of risk.