[pornel]

Go filled a niche that wasn't served well: network services with performance/capabilities exceeding scripting languages. Back then the other options were mainly Java, JVM-based niche languages, or C++ — each with its own problems and detractors. Server-side switching costs are low: if it can talk HTTP, you can use it.

Dart was meant to be a better JavaScript, but the barrier to entry for a new browser-native language is impossibly high: it needs consensus of all browser vendors plus a decade for all users to upgrade. Dart made a fatal mistake of betting on having a brand new browser VM instead of being a good compile-to-JS language. In the meantime, JS itself has improved (ES5, ES6), and TS has been designed for being a first-class JS compilation target. The "better JS" niche has been filled by JS.