It's not quite the same though, there's a light framework involved for defining how the html is inserted, it's over websockets, new request types, etc.
But point taken, I recall using similar techniques a long time ago. I think the pendulum is swinging because front-end development has gone down such a rabbit hole with state management that people are wondering if they can remove all the overhead of redux, translating JSON, client side routing, etc. In most cases, they probably can I reckon.
