A couple reasons- 1) As the cost of feature creation goes down, the demand for features goes up- as others have mentioned, a lot of sites now have an enormous

A couple reasons- 1) As the cost of feature creation goes down, the demand for features goes up- as others have mentioned, a lot of sites now have an enormous number of interactive features or cool rendering that just wasn't there in the good old days of nothing but text, images, and marquee tags. 2) Different frameworks solve different problems, not all of which are related to "productivity." JQuery solved a browser compatibility issues and made interactivity way more approachable, AngularJS did a great job dealing with input and output mechanics, and React is pretty awesome at managing compomentization for large projects. And a lot of frameworks give a "feel" users are looking for. Frameworks improve productivity, but the difference between frameworks is not that great. 3) one thing frameworks do well is allow team scaling, and scaling teams leads to a lowering of "individual" productivity. What works on a team of 1 doesn't on a team of 5. The larger team will need more "overhead." A team of 5 won't be able to do a task an individual could do 5x faster, it'll be more like 2.5x or something. That's not why you scale a team though- you scale a team to take on new problems that can't be solved (or solved fast enough) at the scale you are at currently. I've run a decent size team using angular JS, I shudder to think of our ability to execute using JQuery, even though I successfully accomplished scaled down projects in those frameworks before.