That depends on your use case, I personally really only ever use RSS on my phone. Anyway, as others have mentioned, you can connect the app to FreshRSS for syncing.

Also, feel free to ignore this, but you could probably make your point without being so condescending. Something like "Cool, but the lack of apps across multiple platforms is a deal-breaker for me." Calling someone's work "cute, but [...] useless" after they provide it for free to the community is kinda rude, especially considering it's honestly one of the best actively-developped RSS apps for Android.

it supports FreshRSS.

Why?

You can setup a freshrss server and connect readyou to it

Really, can you elaborate? It's open source, it's free what's there not to like?