Note: Because we are saying fair value, so you cannot account for recession and have to assume normal GDP growth (~2-3%)

In other words "assuming that everything stays in the candyland scenario forever, how can you justify the statement that the market seems overvalued?"

But "fair value" is the historical average over the last 90 or so years, which includes wars, rumors of wars, Great Depressions, inflation etc.

If you are okay forecasting no recessions, no wars, no major inflation, and steady 2-3% GDP growth for the next 100 years, then perhaps the market is not overvalued at all. Maybe we've reached a permanently high plateau, lol ...