For one, it's written in TypeScript. There is one codebase for ES5/6, TypeScript, and Dart. A big benefit of Angular 2 is the better tooling you get with TypeScript and Dart.
It uses things like classes, decorators, and the <template> tag. It uses a virtual DOM, which is still a fairly new concept. It can run in Web Workers and you can even use it for native applications which do not have a regular DOM.
It really is quite different from anything one could have started back in 2009. Even those odd-looking attribute might have not worked because HTML5, which specified a lot of those things more precisely, was far from being done.
Angular 1.x made pretty good use of the things which were available at the time.
It uses things like classes, decorators, and the <template> tag. It uses a virtual DOM, which is still a fairly new concept. It can run in Web Workers and you can even use it for native applications which do not have a regular DOM.
It really is quite different from anything one could have started back in 2009. Even those odd-looking attribute might have not worked because HTML5, which specified a lot of those things more precisely, was far from being done.
Angular 1.x made pretty good use of the things which were available at the time.