The problem is the libraries. Browsers are still mostly incapable of delivering usable workable building blocks especially in the realm of UI. https://open-ui.org/ is a good start, but it will be a while before we see major pay offs.

Another reason is that the DOM is horrendously bad at building anything UI-related. Laying out static text and images? Sure, barely. Providing actual building blocks for a UI? Emphatically no.

And that's the reason why devs keep reinventing controls. Because while details/summary is good, it's extremely limited, does not provide all the needed features, and is impossible to properly extend.