TS is more of an evolution of what exists. In that sense it's a possible "future" implementation of JavaScript -- still keeping the same semantics, but in a more structured way.
Dart is a different language so it's a different path. It's no different than, say, using C# or Java or C or whatever language that can be transpiled to JavaScript.
Dart is a different language so it's a different path. It's no different than, say, using C# or Java or C or whatever language that can be transpiled to JavaScript.