Ethereum abandoned proof-of-work because the temptation to regain abstract power/centralized control authority over ledger writing privilege is incredibly intoxicating to our species.

Satoshi philosophically accepted that might is right and relinquished his abstract power to the most physically powerful. An extraordinary leap of faith and an exceedingly rare trait in the world of software engineering.

The biggest risk in cybersecurity that most people don't seem to understand is how much abstract power it gives people. Developers write logic to effectively code themselves into being neo god-kings with unimpeachable control over people's data. This temptation to have unimpeachable control is what led Ethereum to abandon proof-of-work.

Satoshi created a physical-power-based resource control structure. Ethereum switched to an abstract-power-based resource control structure where it is impossible to physically verify decentralization, and is physically impossible to impeach their control over ledger writing authority.