This is a tautology and reflective of the mindset that produces articles like this one. There is only one Zuckerberg. Unicorns are by definition rare, and disrupting entrenched business interests is rare because they are entrenched. That's what it means.
It only seems like everyone is a founder because that's how it was in SV. It only seems like every stopped creating startups because that's how it is in SV. But like everything else in the world, trends start at the coasts and work their way inward, to the point where SV tech growth may be stagnating or declining, but Midwest startups are booming. And if the Midwest is firing up, African startups are virtually exploding.
Big businesses have always owned every decade of capitalism, and that's not going to change. Economies of scale is too hard to turn away from. But startups aren't dying, they're just taking on less sexy, harder problems that don't impact SV. So of course SV thinks entrepreneurship is dying.
They are people starting their own business. A friend borrowed some money to start a business where he drives a remote control vehicle down pipes to examine them from the inside. The space didn't have much 'local' competition and he was able to spot that, take advantage of it, and now has a dozen employees, has repaid the money, and is seeking to expand his operations. A similar experience was loaning my sibling some money so he could start a plumbing company - except it is more niche and not residential. They use some tech but they aren't tech companies.
It seems to me that the SV pundits see the tech startups while not seeing the guy who does vehicle power washing on-site, the interior decorator that uses 3D modeling and VR, or the folks who opened a diner where they have automated the food ordering process.