I'm disappointed the author glazed over flash loans since it's such a perfect example of something that did't exist previously. The things that "make you dizzy for free" are the things to pay attention to. In crypto I can borrow effectively limitless money _uncollateralized_ if I pay it back within an atomic transaction. Why is that interesting? It's because it's not something that was ever possible before and there's no telling what it will enable. The lowest hanging fruit is stuff like arbitrage where you can now effectively operate without capital constraints but there will assuredly be more interesting uses discovered. Even ignoring the specifics of flash loans, the ability to compose financial primitives into atomic transactions is new.