It's not just that Dalio is a "successful trader." He runs the world's largest hedge fund and their expertise is in predicting global macroeconomic trends. His experience is directly relevant.
I'd read his books on debt cycles. It's novel thinking. Not necessarily correct, but fairly well-researched and presents data in a different view. Nowhere does he say to take the advice as gospel.
Please stop watching Billions and thinking it represents anything close to reality.
What is the max size of asset that can profit 4%/yr alpha from insider trading?