Like it or not, currency systems have long been part of civilization. The types of currency range from gold and silver coins to fiat paper bills to digital, decentralized algorithms. What a proper currency allows an individual to do is have a common method for acquiring the services of goods and services. Barter systems were out-competed by currency in the richest countries, although barter returns after disasters and in the informal economy.
Even the most basic barter system allows one to engage in economic activity. Thus, price discovery, or the ability to accurately determine the cost of a product or service, is a precondition for a vibrant economy. Instead, high frequency trading, short sales, and interest rate rigging reduce the foundation of capitalism to a rigged carnival game. This process has been ongoing for decades, and is unlikely to change, no matter what legislation gets passed (as loopholes can be added). Legal gray areas are often not a bug, but a feature of new laws.
In thriving economies, ecosystems, political, and agricultural systems, diversity is a sign of life. Thriving economies allow for plenty of competition, coexistence of large and small. Although some entities out-compete others, others can arise to fill the void. Thriving ecosystems, such as a forest or jungle, have more types of species than a lawn or parking lot. Thriving democracies have a variety of parties. While some parties may become the most common mainstream ones, it is not impossible for other groups to get elected. An agricultural situation with several types of crops (and multiple species of each) means that a drought or pest is unlikely to destroy all of them.
Instead, we face monoculture in all areas. Markets are rigged to benefit a few big firms. Ecosystems are disrupted at even the microscopic level. Electoral districts are gerrymandered to benefit parties and incumbents. Factory farming has replaced conventional farming as a source of food production. The problem with monoculture is that catastrophic failures become all the larger, as they are inherently brittle.
As these systems fail, others arise outside of the existing legal and political framework. This "black market," informal economic sector is today called System D, as discussed before. As things are banned by increasingly corrupt governments, System D is poised to grow. Furthermore, System D itself is the future of many "legit" firms. The "shadow banking" system comprises the majority of the world's currency reserves, existing in legal limbo in offshore accounts. Somehow, multiple times the planet's GDP in debt was wasted and frittered into this black hole. As something new arises, Ragnarok style, the darkness will turn into the new system.