The key products of the financial system is not transfer of money (which crypto provides) but rather credit (with the associated issues of trust and enforcement

The key products of the financial system is not transfer of money (which crypto provides) but rather credit (with the associated issues of trust and enforcement of settlement against someone's will) and payment for goods and services (with the associated need for fraud prevention on both sides of the deal and reversibility of payments). Mathematics cannot provide that kind of trust.