The promise example is pretty strange (you can rewrite it and it looks much more simple afterwards). I don't have the impression that the author understood the full power of promises.
I think it's aweful that there are so many articles that
1. compare React and Angular with a disclaimer that it is not really comparable (but they do it though from a certain perspective).
2. state that the articles from (1) made an invalid comparision.
I've never seen any benefit (for me personally) from an article of (1) or (2).
This may be true for America but not for Europe from my experience (Germany specifically). A Master Degree makes a huge difference in payment and job possibilities.