If you read the original Bitcoin whitepaper, the idea is brilliant. Unfortunately, many of the original core benefits have been disabled. I still give Bitocoin 4 stars because it has one thing that almost all other projects don't have...no central team to attack.
That could be huge going forward. If regulation clamps down in the future, it's harder to shut down a project that has an anonymous founder.
PoW is still a proven way to secure a blockchain. The idea that PoW wastes electricity is ridiculous. Think about how much collective energy the legacy banking system uses. All of the buildings, computers...and the energy used to get employees to work at these institutions. Transportation energy expenditure is not even factored into this study and BTC still comes out ahead.
Minus 1 star because it has been corrupted and the current version does not operate at full capacity. Research Blockstream and how they limited the early development of Bitcoin.