First of all, you seem to be addressing bitcoin in isolation and not crypto in general. What forces do you think make Bitcoin worth more than ETH or more than Bitcoin Cash? Market forces. Supply and demand. Just like all commodities. These are invisible hand forces that no single person controls at this point. Even if there are varying levels of centralization in the chains themselves, the market decides whether to back ETH or ETC or some mix of both. So, like any decentralized system, the network is monitored in a decentralized manner. The chains themselves have solved for consensus problems. That's the whole thing keeping blockchains going. No, banks don't constantly monitor everything (although admittedly, it's more than ever thanks to technology). Large amounts of cash still flow around the globe. And whether your government is trustworthy depends largely on which of the 195 nations you live in.