Why we should learn angular js

Answer 1

https://www.sololearn.com/learn/1017/?ref=app
here is your answer

Answer 2

The truth is that currently it is not so necessary, although it is a good thing that it can boost you professionally (although it is not as currently used, there are applications written in Angularjs that simply will not migrate to another framework / library).

And in the same way learning one technology or another is a personal choice, in which many factors can influence.