The blockchain network eliminates middlemen and, as a result, elements of the government system. There is no need for a central bank anymore and everything is done under the blockchain chain and by the users themselves. Peer-to-peer transfers between two parties on the Bitcoin network mean that there is no need for middlemen to manage and distribute the currency. In theory, simplifying transactions between people and between different actors on the Bitcoin blockchain could overhaul the current system. The financial infrastructure of digital currency is decentralized, and the power to increase or decrease the supply of currency is not vested in one or a group of authorities. Therefore, in the new structure, the role of governments in managing and regulating economic policies through intermediaries is eliminated.
Blockchain technology actually has middlemen and the middlemen are the crypto miners. They verify the transactions and get transaction fees plus mining reward in return.
Can you buy Bitcoin(or altcoins) without a bank account? It's theoretically possible, but it's very difficult.
Almost all crypto companies are regulated by the governments. Cryptocurrency miners can also be regulated by the governments(most of the miners ARE regulated).
What if crypto miners get banned all over the world? The blockchain could theoretically survive, but there will be a bunch of crypto miners, who are mining illegally.
The government regulation simply cannot be fully bypassed. Some crypto supporters manage to bypass regulations, but there's always the risk of getting caught and getting penalized.