I wish there was a web service that used this tool to scrape nicely-formatted plain text from any website, then archive it and serve it as a super basic web reader.

Not sure how it fares nowadays, but I used to employ Mercury Reader/API for this, now called Postlight Reader[1]. While not perfect, I found it to work for most daily reading needs.

[1]: https://reader.postlight.com/

Concerning tooling I'd say you have two different worlds, JavaScript and Python, each with a series of tools to tackle such tasks. It's not easy to compare them directly because of varying software environments and I haven't had a chance to test JS tools thoroughly.

For the sake of completeness: Mozilla's Readability [1] is obviously a reference in the JS world.

[1]: https://github.com/mozilla/readability