Bitcoin is often criticized for its inherent inefficiency. However, in order to maintain its decentralized nature and, as a result, its resistance to censorship, Bitcoin must be precisely ineffective in order to prevent an attacker or group of attackers from easily gaining control of the blockchain and dominating the network.
Allegedly, the disadvantages of Bitcoin's efficiency are manifested in various ways: each full node of the network must first load each individual transaction, then check each individual transaction, and then permanently save each individual transaction in the block. Hundreds and thousands of nodes in the Bitcoin network store the same up-to-date copy of the blockchain. This massive duplication and redundancy is necessary to allow anyone to independently check the state of the network and registry without trusting anyone else. Similarly, the network security of Bitcoin depends on how expensive PoW mining is: if the block mining is quite complex and energy-intensive, and therefore expensive in financial terms, it will be much more difficult for hackers to successfully perform the so-called" 51% attack " on the blockchain (for example, perform double spending, extract empty blocks, or cancel old transactions) and thus reorganize the blockchain in their favor. It is the energy consumption of mining that forces attackers to spend huge resources in the form of specialized mining equipment and electricity that ensures its performance. What makes it economically impractical to attack the Bitcoin blockchain, and therefore-reliably protects it from intruders.