It is real, you just have to have sufficient funds already to be able to pay someone else to do the active part of the income and make sure they are earning less than their worth so that you can pick up the excess. Most effective if there are many layers in between, so that the income becomes increasingly passive as you move up the chain, so that those under you have something to strive for, because you don't want to be in charge of hiring all of those people, so you hire people to hire those people, each taking a cut of the value along the way.

But don't worry, the American Dream™ is that, as long as you keep working about 10 layers deep in value cuts, eventually you might be able to get into layer 3 or 4 and get your kid into the job early so that they can get to layer 5 or 6, and maybe they'll have enough money to get their kid to 6 or 7.