Libraries like angular and ember are for programming in the large, with lots of code and lots of developers sharing that codebase. They trade simplicity for scalability. You should use them if you know you need them, and if you need them you'll know.
I went through this transition in late 2007, where the app my team was building gradually outgrew simple javascript libraries, and i ended up adopting extjs (the ember of its day) at great cost, but to great benefit. It is 600 kb of js code uncompressed just for the framework, and we not only ended up using all of it, but building a ton of code on top. We needed all that complexity to build the app we work on, but then it is over half a million lines of code by now. If you don't have those needs, the big js frameworks can be more trouble than they're worth, sort of like j2ee vs php.
I went through this transition in late 2007, where the app my team was building gradually outgrew simple javascript libraries, and i ended up adopting extjs (the ember of its day) at great cost, but to great benefit. It is 600 kb of js code uncompressed just for the framework, and we not only ended up using all of it, but building a ton of code on top. We needed all that complexity to build the app we work on, but then it is over half a million lines of code by now. If you don't have those needs, the big js frameworks can be more trouble than they're worth, sort of like j2ee vs php.