http://zestdocs.org/ is my old project I've abandoned with similar idea. If anyone feels like continuing/rewriting, or perhaps even taking over the domain, GitHub organization, macOS app, or whatever really, you can email me via hn at the website's domain. (Note that I've set up the MX records there only a few minutes ago, so it may take some retries to be able to reach this email.)
Kiwix does. But you have to download the dump and run a couple scripts to convert the XML to kiwix archive format (ZIM). They have a repo on github with the scripts. But Kiwix is built on top of xulrunner which is basically Firefox but not supported by Mozilla anymore. And that goes back to my original post why not just bake the offline functionality into the browser.