"What makes business work is creating value. If you're going into the business with the intention of not creating value, but of having it magically provide money for you, then you often make really bad choices. The business that you're investing in or creating doesn't tend to be creating value for its customers or for anyone. So it doesn't tend to spit off the cash you're hoping it will. So many times I've seen people pursue passive income, and end up having active losses instead. They just spend a lot of time and money trying to push responsibilities off on other people and having it not work."
If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.