The problem isn't always the writing. I've bounced off genuinely excellent long-form pieces—articles I later finished and found deeply valuable, simply because the environment triggered my escape reflex before the content had a chance.
It's like trying to enjoy a good meal in a casino. The food might be great, but everything around you is designed to pull your attention elsewhere. At some point, you stop blaming the chef.
That said, you're right that Parsely won't make bad writing good. If an article is hollow clickbait, reading it one paragraph at a time just reveals the emptiness more slowly. The tool helps me get to the content, what I do with bad content is still "close the tab."
Maybe the real answer is both [better filters for what deserves attention, and better environments for when something does].