- Some feeds only provide title/summary and not the full text article (yes, I know there are full-text extraction service, but last time I tried them, none of them was perfect, and I don't want to play the guessing game -- "Am I reading the full article, or a broken extraction?")
- Some feeds are just better to be read in a web browser. e.g.: Project release notes on GitHub, which usually come with links to PRs, commits...etc, so I need to open several browser tabs to consume the content anyways.
- Some personal blog sites have very beautiful (or interesting) designs that I find myself actually enjoys poking around.
- Ad-blocking -- given the current popularity of RSS, I don't know if it really makes sense financially for websites to do so, but I notice some feeds do inject ads.
- If I ever need to click a link in an article, jumping from a reader software to a browser is too big of a context switch that disrupts my flow -- just let me go through all the feeds right now, and I will decide how to prioritize the most interesting ones and allocate my reading time later.
For my use cases, Unread on iOS gave me the best experience. All the gestures optimized for single-hand operations are just fantastic. Sadly, they switched from one-time payment to monthly subscription and I can't justify the cost when I only use it in a very light way(just for sorting items). Reeder is not as good, but is comfortable enough for me.