I covered this in answer to a similar sibling question so see that for in-depth thoughts.

For me personally, it's the coming together of a bunch of things that make it better, I'm not sure I can think of any one thing it does so much better than all competitors rather than just be a very good all-rounder. Maybe ease of code-level configuration counts, (e.g. replacing a function with a custom bit of code as part of "configuration") but not really a "feature" as such.