It's relative. A good plumber with his own small business might make half a million a year. A bread factory probably makes in the low millions, if they're anything like the small businesses (eg. box factories, hot tub supplies, auto repair shops) I know. Google makes $60 billion, and Goldman Sachs makes $11B. That's 5 orders of magnitude.
Plumbers and bread factories make good money compared to salaried W-2 employees (even compared to Googlers, sometimes), but this again is a risk/money tradeoff. When you choose to work for a big company, you are trading off the risk that your efforts will be useless vs. a guaranteed payday that lets the company keep all the rewards if they're successful. In software it's trivially easy to make the opposite risk vs. reward tradeoff: just incorporate the company yourself and get acquired, in which case you get nothing if your efforts are unsuccessful but keep the full market value of your product if they are.
Plumbers make excellent money, not a "little bit". I don't know about bread factories, but I assume they do well too.