With everybody investing on index funds, directly or indirectly through their 401k, does economics ever have a time to catch up? Being out of the market during the crazy hype means losing out on "easy" gains, so basically it keeps going up and up, these companies get even more hyped, and I wonder what's the end game.

I keep hearing that retail investors are just small fry and have no power to affect any stock's valuation, but certainly the hype spreads to big money as well.

Even if I'm way off the mark, I would love to read about what happens to the economy in the mathematically plausible case that people keep buying and no one ever sells enough to mitigate the hype.

The endgame is owning equity assets which represent ownership in companies that make profits? I hold these valuable assets and then sell them in the future. What else could it be?

The assets are valuable because they represent ownership of the most productive companies on the planet?