Reduced energy Consumption

According to reasonable estimates, Bitcoin's current annual energy usage surpasses 140 TWh, while Ethereum's annual energy consumption exceeds 34 TWh. Mining is unsustainable because the energy consumed by Bitcoin and Ethereum miners exceeds the energy utilized by whole countries. Furthermore, mining (using Proof-of-Work (PoW)) hinders real-world adoption of cryptocurrencies since power costs must be paid with fiat money.

However, with POS consensus, validators are not required to do exceedingly complicated computations, which reduces the amount of energy required to validate transactions. To demonstrate, consider the energy usage of two POS-based networks, Xinfin and Tezos, in comparison to Blockchain Ethereum (POW-based networks) shows the massive drop in energy consumption.

Prevents 51% Attacks

A 51% attack is an undesirable situation in which a group or individual gets control of more than 50% of the hash rate of a blockchain network. A 51% attack on a PoW blockchain, such as Bitcoin, grants a person or group the authority to modify blocks. Criminals can easily change the block for their own benefit. Unscrupulous characters conducting a 51% attack would need to stake at least 51 percent of the entire quantity of Bitcoin in circulation using a PoS consensus method. 

While acquiring 51% of a network's trustworthy digital coin is both costly and difficult, a validator would not want to assault a network in which he had a majority stake. To elaborate, when the value of such cryptocurrency declines, so does the value of the staked holding. As a result, the PoS configuration incentivizes stakeholders to maintain a secure network.

Reduced Centralization

The concerns of centralization are lessened with PoS consensus since rewards are determined by the quantity of assets owned and validators are chosen at random. Furthermore, PoS-based networks use governance principles to resist centralization. This is made feasible by the great degree of independence from the hardware utilized for block validation.

Key Concerns

Critics claim that PoS-based networks risk establishing an oligopoly in which individuals with larger holdings wield more power than those with lower stakes. Most PoS-based networks, on the other hand, use a set of governance rules to assure fairness in validator selection and compensate validators for their involvement. The randomness of the validator selection process, as well as the use of various factors in awarding validators, are important issues to consider when selecting and rewarding validators.

Having said that, the PoS consensus has a lot of promise for increasing the real-world adoption of blockchain-based solutions. With the introduction of a PoS-based system in Ethereum 2.0, additional networks are expected to embrace this consensus and reap its advantages.