[CharlieDigital]

    > JQuery was born in a time of server-side rendering (SSR) where, in essence, MVC happened in the back end and it shipped html to the browser.

Yeah, I think this is nail on the head. It was also a time of smaller apps and smaller teams so it was easier to manage the state even with direct mutation on the DOM tree.

With bigger and more complex apps, you needed multiple teams and now it's not possible to really effectively track the state of the DOM if multiple teams could be manipulating it from different components.

You can see that shadow DOM and web components is one way of thinking about this problem. Separating the render from the state (a la Vue, React, Angular et al) is another.