Is Cocos2d-x Still Relevant in the Age of Unity3D and Unreal Engine?

From the view of beginner like me, it’s really hard for beginning. Because Cocos has a really bad document system.

I love cocos because of C++ performance, but no one can help me to solve my trouble.
It can’t do a simple thing like drawing perfect anti alias circle:

The documents about opengl es is hard to find.

I began with javascript (Phaser.io) too but i left it because of performance. It’s suitable for Web game, if you want to build games for iOS, Android. Nothing can compare to Cocos, Unity and Unreal.

You can’t buid a good game with javascript performance.
I’ve tried many games built with javascript, they burn my device battery so fast.