[Zababa]

Good points about JS being a target and that currently evolving. Lots of people these days code without any knowledge of assembly, maybe one day JS will be like that too. On the other hand, if your risk profile is more conservative (like many companies), you may want to let early adopters try out this "JS-less" world before investing in it. Since TS has a huge focus on large projects, and thus large companies, being conservative here makes sense.

For Dart, I wouldn't be so enthusiastic when describing it. The VM, hot reload, and all of that are impressive, but I'm not impressed by the language itself. The language seems to be an incremental improvement on 2005 Java and 2005 JavaScript, which are themselves not great. For example, it lacks data classes (records) and sealed classes. It took a long time to get nullability, the type checker (and system) are not impressive (things can easily fail at runtime).