Is there actually something wrong with the language? If it's a matter of the issue of having to learn a new language, it's not as if there were many Objective-C, Swift, or Kotlin developers before mobile.

Started learning Dart and I like it a lot.

Not sure what the issue is except that it is yet another language to learn.

Google designed it to be easy to learn for other devs. I am mainly only experienced in Java and some Kotlin, and I found Dart easy to pick up.