It makes sense if you look at bitcoin like a speculative asset with a cash value, which is how most people who own bitcoin treat it. Bitcoin has a market cap based on its current exchange value, which is the "pot of money". As more people buy bitcoin, it's cash value goes up, and vice versa.
One can argue whether this adheres to the purist view of Nakamoto et al but this is simply how crypto is marketed to consumers, for better or worse. And in this system, the ways in which these various exchanges and defi platforms facilitate access to blockchain technology through cash transactions ultimately define its value, as we've seen these tokens plummet this year.
> Again, bitcoin transactions merely unlock and re-lock value as an atomic operation. What the author characterizes as "value" is an off-chain phenomenon.
People only care about bitcoin nowadays precisely because of what happens "off-chain". If 1 bitcoin was still a penny, nobody outside the crypto enthusiasts would care more than a decade into this experiment.