Backbone only is not enough to do any serious kind of work today.One always end up with tons of plugins making it as complicated as EmberJS or AngularJS. There is no serious view layer,so one has to use React,Vue,or Ractive. The router sucks,frankly,so one has to replace it. The model layer doesnt handle relationships between model,so one ends up using something else...
There is nothing good in Backbone today frankly.It was one of the first successfull "clientside" framework ,yet refused to evolve(like underscore or coffeescript today),refused to incorporate good ideas from third parties that would have made it still relevant today.
There is no future in Backbone.Maybe there is still a place for a Backbone like framework that would still be based on jQuery and would incorporate a better view layer. But Backbone itself is dead.
I personally prefer AngularJS ,not because of its directives but because I strongly believe in IoC containers over any other way to build and wire objects. But I think EmberJS is as good.