I wouldn’t say useless, that’s too negative. Maybe “not very insightful”. To be clear, it’s not a bad book.
I think that if you’re into personal finance, also the more philosophical aspects of it, then you’ll find many things that you might already have read elsewhere.
Books like “Early Retirement Extreme” by Jakob Lund Fisker, “Rich Dad Poor Dad” by Robert Kiyosaki, or “Sapiens” by Yuval Noah Harari, especially the chapters where he speaks about work and the economy. Many of the books of Nassim Taleb also come to mind.