Comment by PaulHoule

Sometimes I think the techniques we used to build complex user interfaces in HTML without AJAX or DOM manipulation back in the early 2000s are effectively lost, like the techniques used to build the pyramids: insofar as younger full-stack developers have been "deskilled" many of them think you need Javascript to, say, validate forms.

Once you are using AJAX and manipulating the DOM the complexity of asynchronous communication is going to lead to something of a similar magnitude as React. Sure you can write

   document.title="A new title"

and not have to bring in <Helmet> but even if you think of front end as "just" updating the UI when data comes in from the server a complex application may need to update several bits of the UI and at some point you need to create some kind of communication or state management bus that handles that. Could it have been done differently? Sure.

If there's something wrong with the Reactisphere it isn't that it creates an abstraction which other abstractions live on, but these are leaky abstractions. You could use something like Bootstrap or MUI without understanding CSS if you are making something very simple and don't care what it looks like (don't have a marketing team who cares what it looks like!) but to do pro-level work you can put in front of customers you have to understand HTML, CS, JS and all the the frameworks used in your project.