Ask HN: Best Framework for Web Games?

I see that Unity compiles to webgl, so what are the benefits of using things like Phaser? Is there something better than Phaser?

Currently I'm tempted to just use Unity because then you can have one codebase for mobile app and web (or is there an easy way to turn a Phaser game into an app) and because then a single dev team can do 3D, 2D, apps, and web-native.