As i read capyreader as a rss reader for a freshrss installation, i have one small tip:

Sometimes, the website works good enough that you dont need an app for it.

Yes you can argue, that you would always need internet connection if your reading your rss feed. I am personaly fine with that.

So sometimes, the answer to an app is to just use the website

I really respect this eyes-open view of degoogling/FOSS-ing. We can do a lot, but some of the all-or-nothing rhetoric on Lemmy is exhausting. Yes, sometimes living in modern society still requires us to use some non-free apps. You've gone far beyond what most people would do in this sort of situation, and even you have reached a point where dealing with other people or necessities of life requires you to have some Play Store apps; so you do what you can to lock them down, but accept that some things are just going to have to be less than ideal for at least a while.