People are giving you the starry-eyed entrepreneur version, which builds its rhetoric on how they're "changing the world", how they're motivated by learning and pushing the boundaries of what's been done and what is possible, and so on and so forth. Here's a counterpart explanation that some may consider a bit more cynical, built after some time in SV working for early stage startups, advising some early stage startu…
"The people who are really bringing in the big bucks are VCs/investors/incubators/etc (with the real estate and media companies coming in in second place)." During the California Gold Rush (1848–1855), few actually got rich from gold. The ones who really got rich were the ones who provided services (bar, housing, food, etc) to the people rushing in to find gold. History does repeat itself.
The market of visible gold nuggets or quick MVPs may be over-saturated. Gold diggers invest a minimum of thought, equipment, know their chances are getting slimmer and depend mostly on luck.
Very few startup gold diggers can try a different approach, because it's all about starting with minimum capital and preparation. Big capital got mismanaged too often, so there's an over-correction.