I don't really disagree with you regarding the cause of the HTML stall as hypermedia, although I still claim that it was the stall that directly pushed people i

I don't really disagree with you regarding the cause of the HTML stall as hypermedia, although I still claim that it was the stall that directly pushed people into JavaScript maximalism. The JavaScript maximalist era didn't really come into existence until post 2010 with the release of Angular, which was two years after the release of HTML5. HTML5 included canvas as a reaction to flash (and the long-since-effectively-dead java applets.) So HTML was making progress, but that progress was mainly in terms of front-end, thick-client style features, driven by, yes, the JavaScript (and flash) technologies. But what it wasn't doing was making progress as a hypermedia (e.g. adding new hypermedia controls or, as with htmx, making all elements hypermedia controls.) As to the cause of this lack of progress as a hypermedia, I agree with you that it was due, at least in part, to the other front-end technologies, as well as a lack of appreciation for the hypermedia model (which is why I mention the thought leaders going down the webservices/JSON API rabbit hole.)