Overall I prefer Instapaper to Feedly due to the minimalist design and dark mode on mobile. However, there are strong arguments for either one.[0]
Additionally, I use Feedly[1] to discover content from sites in an RSS-like system. I find that visiting Feedly daily in the browser, then saving content to Instapaper using a browser extension for later works optimally for me.
[0] https://medium.com/@janniks/instapaper-vs-pocket-2019-compar...