First of all, Kotlin and Dart are made by different companies. At the same time, use cases for these languages are very similar. Both companies claim the languages to be good for backend, front-end, mobile, desktop development, scripting etc.

> you're mentioning features that do not make Dart a more useful language

They would do Dart a more useful language for me.

> Dart is very good at doing the nice things of oop while keeping it simple

If you like Dart as it is currently, that's great. I don't

> Dart was written with the pilosohpy in mind to be easy to learn and without a lot of surprises, and they made it work. But I can't say the same about something like swift or kotlin.

Well, a different story for me. I don't think that Dart is easier to learn, or that Kotlin is full of surprises.