Also, the quality wasn't there on what you shipped. The form controls are ugly and non-functional. They needed to be designed, *by designers*! Not everything is an engineering problem.
You only kind of achieved the first part of the extensible web manifesto, and never even tried the second part (paving the cow paths with higher level solutions).
And now the WhatWG is as stuck as HTML/XHTML ever was at the W3C. Maybe even more so. You got so much done, but by force of personality instead of systems that encourage contributions from lots of diverse people. Dictatorships are never going to work without the benevolent dictator. They are inherently unstable systems.
The focus on web components was a decade+ long distraction that didn't take into account the needs of framework authors but instead saw them as a competitor. It was a solution looking for a problem. I interviewed around 30 developers and almost all of them said they either tried WC and didn't like it or hadn't tried it and didn't want to.
* One dev said, "web components only kind of fixes a problem I had 10 years ago." * Another, at a co that uses WC extensively, said, "web components are a solution to big company problems but know using them will add a year and a half to any development timeline." (paraphrasing, but you get the idea) * Even a company built around web components said that it wou ld really be better as separate technologies rather then bundled, "give me style scoping separate from templating and slots".
You didn't solve the problems devs find challenging. Frameworks do. The existence of frameworks on the web is a feature, not a bug. And the reasons people use frameworks are diverse, but range from: team dynamics (having one right way to do things, documentation, easier to TL) to literally making it possible for devs to ship the features they are asked to ship. You can't really argue with, "I couldn't build these complex features without frameworks". These devs don't want even lower level solutions.
Developers mostly don't want the assembly language of the web, they want their chosen frameworks to have excellent DX and the UX they produce to be fantastic. When we see frameworks as a core customer/partner for web APIs, things turn out a lot better.
And, now for my childish moment, I told you back then about design systems and the need to support them properly. I told you it was the way folks were going to be building UI soon. You didn't listen. And that set the web back 10-15 years. I literally had to get a job as PM of Web UI at Chrome to correct this mistake. That is happening now. We're shipping container queries, scope, nesting, style queries, state queries and a host of other features devs tell us they need to architect component systems. I know "people are going to be building pages made out of 100s or 1000s of components" probably sounded wild at the time, but that is the thing about listening to your developers, they know what they need. They understand the biggest problems they face. As a PM, every day I assume I don't know what devs need, so I ask them.
HTML is an incredibly accessible technology for nearly any new developer, designer, or content creator to learn in a basic way. That is a strength that should weigh in heavily. We don't need to throw out HTML and CSS... we just need to fix mistakes that were made.