Ugh, and that only months after Omnivore (a really great FOSS "read it later" app) shut down. The one constant of "save your favorite articles and websites offline, forever" apps seems to be that they're... very much not forever. In my view, this not being a native, interoperable feature of web browsers is a failure of the web. I'll be able to listen to a podcast episode I've downloaded as an MP3 forever, and the sam…
I just Ctrl+P print the reader mode output to PDF. Takes 1 second. I've been doing it for years and it works perfectly. I have articles I saved from a decade ago in Dropbox. I'm honestly surprised people use a whole app for such a trivial feature, but yeah it's fair to have special needs. For me, Firefox reader mode is all I need, and you can just save it as PDF.
Even on my computer, not many pages have a nice print stylesheet, and the result frequently looks horrible/nothing like the original page.