If the goal is to build a browser, then everything else (the alternative ecosystem, the alternative OS, the alternative hardware, the custom chips for the hardware, etc.) not required for the actual browser is waste. That's the exact opposite of efficiency.
The issue isn't chrome's ecosystem. The issue is that Chrome is being used to create unfair barriers of entry for Chrome competitors which then allows Google to use Chrome to harm consumers because there are limited competitors for consumers to switch to.
What is a quality alternative to Facebook? Diaspora was DOA, Mastodon is a cesspit, Twitter is nothing like Facebook, and G+ is long-dead.