It's not just that the idea has been developed over and over, but it is constantly hyped as a return to the golden past, and yet never gets the love that new client side spa messes end up attracting.
htmx was a mashup of $.load(), pjax and angular 1 style attributes (very different conceptual model but I saw how angular used custom attributes and thought that looked better than the JavaScript api I had cooked up)
later on I figured out that what I was doing was generalizing hypermedia controls, but that took me years to figure out.