So.. There are benefits to this for complex apps - but 90% (charitably) of this kind of code is not in a complex app. I think it's for two main reasons: 1. If

So.. There are benefits to this for complex apps - but 90% (charitably) of this kind of code is not in a complex app. I think it's for two main reasons: 1. If you don't use complicated new technology you won't get a job doing web dev. 2. Many new JS devs don't understand JS/HTML/CSS well, they only understand a particular framework - and even then not in a sufficiently deep way. When you come across a seemingly normal site that requires JS in order to display anything, it's pretty unlikely that anyone involved ever considered not doing it that way.