Feeder on Android is my pick. Thunderbird does RSS, and I already use it for email, so it's a nice all in one on Linux. Both can use OPML files to import/export your feeds.

Self-hosted FreshRSS to grab the content and reading on a Proper Browser. NetNewsWire as a mobile reader that connects to FreshRSS.

I run Miniflux on a Digital Ocean droplet, and Miniflutt on my phone.