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.