Earlier quoted context omitted.
It's completely different from ES6, it's a full-stack framework, so it does SO much more than just a front-end framework. Meteor's main selling point is the reactivity; you can call `Books.insert({ name: "test" });` on the client, in-browser and it then updates the UI optimistically, updates the DB on the server AND propagates the change to all other clients, which in turn updates their UIs. All with one line of code…
Is DDP or Meteor really needed though? Couldn't you easily set this up with RethinkDB using its Changefeeds killer feature for real-time + socket.io along with whatever other library/frameworks you want to use without ever touching Meteor?
I think the main benefit of Meteor is not that it's impossible to do what it does with other libraries/frameworks, but how easy it makes those things for you.