Yes, that's true. I'm not saying that the US is necessarily at its peak, just pointing out the fundamental problem with extrapolating based on historical data.

Yes, that's true. I'm not saying that the US is necessarily at its peak, just pointing out the fundamental problem with extrapolating based on historical data. It assumes that the future will look like the past, even though there are some plausible reasons to think that it won't. Some of those reasons would push you harder in the direction of investing in stocks (e.g. increasing automation, globalization) and some would push you in the opposite (e.g. declining gdp growth, rising inequality, political instability).