what js framework should I learn? [on hold]

I spent the whole day learning angular js and end of day I feel angularjs is difficult to learn.

Honestly, who likes to make their lives more difficult? The learning curve is steep. Even to make a simple form validation there has to be lengthy custom directive written for it.

For example:

• No spaces in the input text box
• Number only text box
• Trimming the ends of input values etc

For all the above I didn't find a easy way out. Now tell me which framework should I choose for a web application I am going to create. From the research I found the top three if I am not wrong:

1. AngularJs 2. Ember 3. Backbone etc

My web application will be for telecom service provider where they can process bills to customer including campaign management, on-boarding a customer etc.

Can any one please guide me through. I have also seen reactjs which is competing with angularjs lately, but it is not a mvc like angular.