I self host tiny tiny rss (tt-rss) in my home lab and access it using Firefox. Then I read articles with the Firefox reader view. Being visually impaired I like the larger text available.
I use a self hosted instance of tiny tiny rss (tt-rss) for subscriptions and Omnivore for reading.
Omnivore is open source with no data collection.
The iOS app is very good with integration for saving items from the firefox web browser.
The web app works well on the Linux desktop with the Firefox addon for saving articles.