The 2010s were a great decade for stocks, the 2020s might not be. That too changes the psychology.
The good times in stocks were supported by very low interest rates, which some people call "financial repression" -- despite that there was tremendous demand for "stablecoins" (government bonds) even at negative real interest rates.
Even if you believe conditions are right for technological and social progress, interest rates will be a headwind for the stock market if they revert to the mean.