I think that, for me as a newcomer to front-end development, this is the biggest takeaway: a framework component is a reusable block of javascript while a webcomponent is a reusable HTML element.

As a newcomer[1] it does not make sense to even learn the front-end frameworks. As an example, the time spent in learning the entire framework simply so I can 'watch' an element's value for changes, or propagate an element's changed value to other elements is going to be order of magnitudes greater than simply writing 3 custom elements that monitor and propagate values for any child element.

(PS. I like your post. I think a followup blog post with two concrete examples may make sense in refining your thesis:

Example 1. This is a popular React mechanism to do $FOO, here's how it is easier in a webcomponent.

Example 2. This is a complex webcomponent, here's how it is easier in React.)

[1] One who is not looking to put "react", "vue", etc on their CV.