i guess 'possibly' the holy grail could be the laraval/rails/django mental model of serving routing and page behavior from the bandend, however using the same language for back as front and having things linked up in a typesafe way. wouldnt be perfect for every situation but would have a good mental model when youre developing a web app type of product where there's little distinction between front and back and theres only one client in mind for consuming server behavior.

Now with htmx, you can actually just generate the html in the backend and send the fully formed stuff to the frontend. No need to JSON-Api-fy everything first, then de-jsonify again in the frontend.