That book is really about Tim Ferriss figuring out how to automate and delegate everything in his business, until he only has to put in 4 hours a week to keep it going.
Until you reach a similar point, as this article shows, you don't really have any "passive" income. You just have another job.
I think it's common sense that the title was chosen for marketing reasons, not as a factual description. (iirc He even talks about testing titles for the book in the book)
I do believe there could be weeks where it's only 4 hours of maintenance. But no one in their right mind believes they can build an asset base of recurring income sufficient for living on 4 hours of total effort per week. The real message of the book was about arbitrage. Geo arbitrage to live somewhere that costs 1/2 the price to work 1/2 as many hours. Eliminate the "80%" of the low value work. Use the same arbitrage to outsource the remaining low value/low skill work. Only do the high value hours yourself.
That book is really about Tim Ferriss figuring out how to automate and delegate everything in his business, until he only has to put in 4 hours a week to keep it going.
Until you reach a similar point, as this article shows, you don't really have any "passive" income. You just have another job.