The drawback is that it's using Readability to process the page, which is not always reliable (that's why the Joplin clipper has both the "simplified" and "full" options). It also won't work with JS-heavy pages or those that require login, but still it's quite useful to grab simple pages.
Beautiful app. This should be incorporated as a web clipper for Joplin.
Did you take inspiration in Firefox's Reader View?
Firefox's functionality is sufficiently reliable as to be a default, given the fact of what it is intended for. Maybe we shouldn't have a web clipper for Joplin but Joplin's "Text Clipper"? Joplin's "Reader Clipper"? I hope the idea is clear. I think it is a good one, and we are fortunate to have this app already developed.