"[RSS is] an easy way for readers to quickly discover released and updated articles." This is true. And there's nothing in that statement about how frequently a site updates.
Telling sites to reduce the number of entries in a feed and telling users to decrease the refresh frequency is a bad idea for sites that update frequently. Very few self-hosted rss readers allow for per feed refresh rates (freshrss is the only one I've found that does I think) so to capture everything on sites that update frequently but have tiny feed sizes I have to run separate cronjobs. That's after asking them to increase the feed size.
Having readers honour HTTP Cache-Control / Expires headers and/or RSS skipHours would allow the server side to control things, dynamically if necessary. Eg, after a bit of discussion, and bug fixes on both sides, Feeder (SpaceCowboys) is now interacting with my feed well in terms of polling rate, while Amazon and Apple continue to blindly pound me (even with gzip disabled for Apple!) every few minutes for a feed that updates ~monthly...
Telling sites to reduce the number of entries in a feed and telling users to decrease the refresh frequency is a bad idea for sites that update frequently. Very few self-hosted rss readers allow for per feed refresh rates (freshrss is the only one I've found that does I think) so to capture everything on sites that update frequently but have tiny feed sizes I have to run separate cronjobs. That's after asking them to increase the feed size.