It's rare for individuals, because a patent costs ~$25k to file and maintain, and the process takes ~5 years. Patents are narrow and taken out very early in the inventive process - so prone to being irrelevant or silly. The really valuable patents - fundamental ones - are particularly risky. This adds up to meaning that the mass insurance of corporate sponsorship is the only way for inventors to profit (marginally, and as a group).

The inventor of the B&D Workmate has earned a 3% royalty on 55 million sales. That's almost certainly over $100m. It's very rare to make a lot of money on a patent, but for something popular let alone ubiquitous it's entirely possible.