An app that is open source and can extract the page content in a simplified “Reader Mode”.
This might not fit your workflow, but Thunderbird can be used as an RSS reader. Go to File > New and add a new Feed Account
I was hoping for this to work but it doesn’t parse the full content. Weirdly also it didn’t import correctly the opml file, the folders where there but they didn’t have the rss link.
Emacs
FreshRss! It’s a selfhostable web app/server with a browser reader.
The full text extraction takes some technical fiddling and reading, but it works like a charm!
Can’t go wrong with Fluent Reader. It’s beautiful and featureful, has a reader mode as well.
Miniflux has grown on me https://miniflux.app/
I run it in docker and access from browser. It says it can automatically download the whole article. For me I have to hit download button each time, maybe I missed some configuration.
If you self-host services, I recommend it