Ask HN: What features should the “ideal” RSS reader have?

I am planning on making an RSS reader because I don't really like the ones that are available. Most of them are freemium models which I always have some wariness with using since they usually get subsumed by bigger companies (flickr, delicious, instagram, firebase, instapaper, etc) and often discontinued.

I really believe in Pinboard's business model, and I think that an RSS reader using their business model (subscription model) would be really successful.

My question, What features would you want in a completely reimagined RSS reader? (Don't worry, I'm not planning on removing the proverbial headphone jack from the RSS reader)

It can be ideas that are totally from left field, or features that aren't even negotiable for an RSS reader to have. Don't worry if you'll sound pedantic. I really enjoy listening to pedantic feedback.

Thank you for your input!

==== miscellaneous ====

In preparation to making this RSS reader, I built a clone of the FeedlyCloud product (https://app.pub.center). Basically it archives RSS feeds, offers a free REST api, and will charge money for push notifications. It's janky right now, but works.

VICE gui: https://app.pub.center/feed/37501716aa216d5cc7612ab8db01ecc3a87cda50 json: https://pub.center/feed/37501716aa216d5cc7612ab8db01ecc3a87cda50/articles

WIRED gui: https://app.pub.center/feed/76348e6bc3cbe5491ec9301b78e20fada87839f9 json: https://pub.center/feed/76348e6bc3cbe5491ec9301b78e20fada87839f9/articles

NYRB gui: https://app.pub.center/feed/5c965c127c0281698e7199d2468117a54c76983a json: https://pub.center/feed/5c965c127c0281698e7199d2468117a54c76983a/articles

This will be the platform that my proposed RSS reader will run on. I want to mention this to show that I'm serious about making this thing. Thanks again!