The power of compounding interest truly is incredible.
Bank of America found that if an investor missed the S&P 500's (index) 10 best performing 'up' days in each decade from 1930, their total returns would be just 91% after 80+ years. This can result when trying to 'time' being invested in markets (boom and gloom). The best gains often appear from nowhere and in the midst of gloom.
Had the investor not tried to time markets, stayed invested and took the bad with the good; the return would have been an astonishing 14,962%. Yes you are reading this correctly. This period included massive market swings, crashes, sideways movements lasting years and all sorts of political and economic dramas. they give no indication of any residual surplus or its size, if any.