Name a Major Cryptocurrency That Successfully Transitioned from PoW to PoS

Ethereum (ETH) is the most prominent example of a major cryptocurrency that successfully transitioned from a Proof-of-Work consensus mechanism to a Proof-of-Stake mechanism. This transition, known as "The Merge," occurred in September 2022.

The move was primarily motivated by the desire to drastically reduce energy consumption and improve network security and scalability.