https://netnewswire.com/

Though it may not meet your criteria around infinite retention. The developer has written about their philosophy on that here: https://inessential.com/2018/10/13/netnewswire_article_age_l...

I wrote my own from scratch including the HTML/XML parsers. If you can't pick a reader the next best option is to write it yourself. There are countless projects on GitHub in any language.

Probably not really usable for anyone except myself but here is the code for my reader: https://github.com/vborovikov/news

I self-host Tiny Tiny RSS (https://tt-rss.org/). I think it will do everything you want (and more). The web UI is fine, and the Android app is great. It's actively developed, has been around for over a decade (I have been using it since Google Reader shut down) and has been super stable.

I guess the only thing it doesn't have that a SaaS offering could do would be some sort of recommendation engine (which I have no interest in).

I have found this article https://www.tecmint.com/best-rss-feed-readers-for-linux/ and has some nice self-hosted options.

From a desktop app's point of view, I have tried liferea for a while and liked it a lot.

I'm not using anymore though, because the websites I used to follow went behind captcha mechanism(s) and cannot fetch their feed any longer which saddens me just by thinking about it.

Have you checked out https://lighthouseapp.io/?

Feedly has a freemium model. It certainly allows tagging feeds; don't think it allows tagging articles

https://en.wikipedia.org/wiki/Feedly

Have you tried https://www.freshrss.org/ ?

For a nice UI, I'd personally use Read You on Android, and NetNewsWire on iOS

Miniflux

Seamonkey. With a bookmarklet to go to the archive version of the current page (to bypass paywalls), it can do everything you want. If, as suggested by your want of self-hosting, you want something centrally located that will allow you to seamlessly track feeds across devices, all options suck, whether paid or free. You're probably better off just writing a program in your language of choice (I've never seen a language without one or more RSS/atom-specific libs, let alone plain XML) to meet your own needs rather than banging your head against the wall of someone else's pet that does what they need but isn't perfect for you.

You didn't mention a mobile app or cloud sync as one of your priorities, so any offline, desktop RSS feeder should provide most of these features.

I use Elfeed in Emacs, which satisfies all your requirements -- except bypassing paywalls -- and is the best RSS reader I've ever used. For context, I've used at least ten RSS readers since 2005 before finding Elfeed in 2018.

FreshRSS might be worth a look. Has most, if not all, of what you're looking for. The paywall ladder might require a plugin.

emacs elfeed