Is it possible to develop full-fledged Android applications in JavaScript?

Question

JavaScript

Is it possible to develop applications for Android in JavaScript that could reach the world level? If not, then in Java?

Answer 1

You can... but you don't have to. WebView is one of the slowest android elements, if it is something with content then there is no problem, but if you want a responsive interface then Java.
For ios, I don’t know everything is so sad, but I didn’t feel it with my hands to form my opinion about the quality of applications on js for android, just go to the phonegap site or a similar framework, there are examples of programs implemented on them ...
If all this is due to unwillingness to learn java you won't get any gain.

Answer 2

If not, then in Java?

Java is the native platform for android, so yes.
It is possible, but more expensive and more difficult than in Java (profit only with the support of at least two platforms). There is also native-react from the interesting.