Money you can pay taxes with is the specialised kind of money: “state money”.

You limit yourself in some ways if you consider state money to be the only money. It ties you to your state: which is OK when you agree with your state, but sucks when you don’t. It ties you to the state’s economy (the problem these novel/local currencies attempt to solve). It ties you into statecraft, international relations, and the horror show that is global currency exchange. It invites the state into every transaction you make. It invokes your state’s monopoly on violence, with every transaction you make.

All these have their uses, but they are also a burden sometimes.