I've been using one of the numerous "RSS to Email" programs for the past 20 years.
To me that's peak usability, I can use my mail workflow to have cross-device state, I can use my mail clients tagging and spam support to filter, and I have a reasonably good searching facility too.
Some sites only include "teasers" rather than full posts, but they're a minority.
I’ve setup a local RSSBridge instance and use its “CSS Selector Feed Expander” module to expand these feeds into full feeds.
They also have a public instance.
https://rss-bridge.org/