ELI5 style explanation why Proof of Stake is inherently inferior to Proof of Work:

In a Proof of Work based system, it's impossible to permanently take 50%+ control of the network, as it's impossible to prevent new miners from joining the network, even if you have 50%+ of current mining power. In a Proof of Stake based system, it's inevitable that someone will permanently take 50%+ control of the network, as when someone buys up 50%+ of all existing coins, their stake will only get bigger and bigger, and it's impossible for anyone to ever overtake them.

As specifically regarding Bitcoin vs Ethereum:

Based partly on smart decisions and partly on luck, it came to be that there's no "leader" in the Bitcoin community. Satoshi Nakamoto left the project over 10 years ago. Satoshi's "successor" was Gavin Andresen, who, a few years later, managed to completely discredit himself in the eyes of the community and haven't been involved with Bitcoin since 2016.

Ethereum has a very clear leader - Vitalik Buterin. While Vitalik obviously doesn't have any direct control over Ethereum, his word is followed by the Ethereum's community as gospel. That would be bad enough in itself, even if Vitalik Buterin wasn't a Russian guy close to Vladimir Putin, which he is: https://www.coindesk.com/markets/2017/06/05/vladimir-putin-and-vitalik-buterin-discuss-ethereum-opportunities/

Edit: typo.