Efficiency is not Bitcoin's core value proposition. Security through decentralization and massive mining power is. It was intended to become digital cash but it turns out it works much better as a store of value, which is one aspect of money fiat sucks at.

Bitcoin must scale through second-layer solutions such as the Lightning Network.

Steem is built for a totally different purpose. It's an app-specific chain to serve as the backbone of Web 3.0.