Since when is the Safari Reading List a cloud service? It might be that I just have most of iCloud disabled and that makes the system work as expected, but for me it is definitely 100% local (at which point I would presume failures are due to the mechanism it using to save things not working on all kinds of web pages: I honestly only use it for simple document sites, and so wouldn't know if it fails a lot on rich web app sites).

I think perhaps they're annoyed that their Reading List isn't syncing between their devices and Apple hasn't put a button that forces the sync to occur.

Yes, it is advertised as being able to make it available offline. But if you save it to reading list on iPhone, or your Mac, there's no guarantee it's available on the other device and often it even stops working on the device that I added to reading list.

Until Firefox broke its extension API there was an extremely useful extension called Scrapbook that could you could point at a website and save that site and all linked site (with settings for how far to recurse and what URL patterns to accept.)

FTR: I still use Firefox as for me the alternatives are worse. As someone else mentioned Pocket exist and while the communication around it could hardly been worse it is still way better than Chrome IMO.

Oddly enough Mozilla gets crap for it but they bought Pocket which allows for offline reading. I think its fine for Mozilla to include Pocket. We seem to be fine installing Chrome which has much worse spyware. You can uninstall Pocket, you gotta go through more effort to uninstall Googles OS from Chrome.

Exactly the reason I use Opera on Android devices. Does not save movies or odd file data but html + images perfectly and web pages looks like originals. I use it a lot to save pages for offline viewing during flights. Now Vivaldi is on Android too and I hope it does have the same feature.

Offline users don't generate data/ad impressions, so offline user experience isn't considered.