Sad to say, but in the history of prospecting, very, very few prospectors have ever made big bucks. The people who do so are the mining companies, and the people who sell supplies to miners.
Most prospectors after a hard day’s work end up with just enough gold to scrape by. Typically they earn less than minimum wage.
Plus the whole business is full of scammers, con men, rip offs, thieves, and bureaucrats who want to horn in. Any field or mine that is sold has probably been salted.
And every sucker will swear to their dying breath that the mother lode (increasing concentration at depth) exists. It does not. This is known to every serious geologist.
The show exposed this fact about the Klondike gold rush. The show includes a little bit of history and science, presumably because it's on the Discovery Channel. If my understanding is correct, modern mining techniques allow gold miners to revisit previously mined areas and extract gold that was overlooked/unextractable using the older techniques.