I loved jQuery when it first appeared, but it is from another era, for sure. The rise of the Single Page Application was one big strike against jQuery. Frameworks such as Angular 1.0 emerged which relied on jQuery, and the software built with those frameworks revealed the dangers of mutable state, especially when combined with something async like Ajax. Anyone who has worked on a large Javascript project is eventually burned by mutable state. Then other frameworks such as React and Om Next emerged, which advocated for immutable data. The team behind Angular realized their mistakes and tried to fix them, so Angular 2.0 was a radical re-write of Angular 1.0, and yet despite that, more and more developers continued to flock to something like React. The immutable frameworks offer the idea that all state should be held in a single immutable atom, and the views should merely be straight reflections of the state that is held in that atom. One could still potentially use jQuery in the background to handle the actual update of the DOM elements, but there are many other ways of updating DOM elements, and many of those other methods are more efficient than jQuery, so jQuery's importance has declined.

Back in 2007, if you wanted to add some simple visual effects to your CRUD app, then jQuery was like a gift from God. But nowadays, given the complex systems that people are building, jQuery has less to offer. It never had an opinion about managing state, so it leaves the core question of building a large app to other frameworks, and those frameworks have various built-in ways of updating the DOM, so the ease-of-use offered by jQuery is no longer such a noticeable advantage.