It's easy to see it this way, but unfortunately it doesn't work like this in practice. "Something you can pay with" and "something you're expected to pay with

It's easy to see it this way, but unfortunately it doesn't work like this in practice. "Something you can pay with" and "something you're expected to pay with or you're out" can describe the same asset, but are much more driven by the relative power of the person being paid. We tend to honor the former (as you do) until it becomes the latter (as it mostly seems actually is when it's allowed).