I’m using Feedly Classic on iOS. I would like to move off of it, but I have yet to find any other RSS client which presents the articles in a card like view which you can vertically swipe through to mark them as read.
Feedly themselves abandoned this UI for an infinite scrolling list on their main app. All other RSS clients I tried have this similar UI, which I feel is really poor.
Proprietary software is also really dogmatic. Steve Jobs famously didn’t support flash on the iPhone, there also was no direct access to files/file system in the UI for a very long time. Tim Cook told someone’s Mom to just buy an iPhone to access iMessage. There’s too many user hostile dogmatic positions from Apple.
I think this has nothing to do with open source vs proprietary, but rather specific individuals having power/control over the software to force specific decisions.