I am shocked and feel kind of betrayed that the de facto "Web documentation" moves away from using Web technology for static documents to something that treats the Web as a broken runtime for apps.
Furthermore, it's fast and it looks good. What's the problem?
There are a lot of web standards. XHTML and XSLT are web standards. Server-side rendering is web standard. Being able to save a page with search results and view it online used to be standard.
Some standards are better than others. Some are objectively bad and promote hazardous and error-prone practices. ActiveX is a standard, that was meant to turn Web into platform for running Windows applications. It did so by giving web developers access to powerful programming languages and diverse range of APIs (some of those APIs were a bad idea by themselves). All modern Javascript web frameworks are spiritual successors of ActiveX, and I sincerely hope, that they will end up in the same garbage dump of history where it did.
ECMAScript however is open, very well-supported, and actually works. I see little connection between today's JS frameworks and ActiveX controls. That seems like a stretch of definitions.
XMLHttpRequest used to be a popular ActiveX control, that introduced ability to programmatically perform web requests at programmer's discretion. Most modern Javascript frameworks can't be used without such ability.
Besides, today XHR is being replaced with the fetch API.