Paul Graham addressed this in his previous essay "How People Get Rich Now":
The best way to envision what happened is to imagine a pond with a crust of ice on top. Initially the only way from the bottom to the surface is around the edges. But as the ice crust weakens, you start to be able to punch right through the middle.
The edges of the pond were pure tech: companies that actually described themselves as being in the electronics or software business. When you used the word "startup" in 1990, that was what you meant. But now startups are punching right through the middle of the ice crust and displacing incumbents like retailers and TV networks and car companies.
That "pond" metaphor only works if anyone and everyone getting rich anywhere in the world all happen to be doing so at the companies that are popular topics of conversation within the Valley bubble.
Otherwise, what the fuck is he even going on about?