When should I start using a JS MVC framework for my front-end applications over a server-rendered application?
This means that you have nested routes or various components on your website that depend on data retrieved from the back-end. I found it harder to build maintable, ambitious UIs using only JQuery without losing my sanity.
In certain applications, you might want to persist certain information across different views. It is kind of harder to persist information such as the "Current User" that is logged in and that information is needed across all views.
All your services may not exist on one server, you may have to make posts to different URLs/services for different functions of your application . . .
If you are trying to build a front-end application using only JQuery and you find yourself setting a lot of pushStates or manually updating the window.location.hash within your front-end code, you might want to consider using a front-end framework or library such as React.
If your front-end makes multiple queries to an API and has to update your front-end according, rather than having to dynamically remove and recreate the nodes using JQuery, it'd be better to just abstract the relevant data/information and their actions in the Controller and leverage the strength of front-end templating in the View layer to present said information.