What makes anki not suitable for "incremental reading" ( interleaving between reading and remembering) ?
Incremental reading works by breaking down an article into flashcards. Basically, you go: article -> paragraph -> sentences -> flashcards (usually with cloze deletions). But, because the algo manages when you see everything, I don't have to worry about doing all of that in one step.
Polar Bookshelf (getpolarized.io) is more of an open source solution for archiving documents at the moment. You can export annotations/extracts from Polar into Anki, but you don't get the spaced repetition with the actual reading of articles like you do with Supermemo.
I read a bit of the article, decide if making an extract of that portion is worth it, and then click next repetition when I'm done/bored reading it. I'll then get another article/flashcard/extract (of another article).
You also have tools for marking up articles and saving your place.
Every day I review around 30-50 flashcards, and 30-50 articles/extracts of articles.
With Supermemo, I don't have to decide (or rather, I give up the ability to decide) what I'm going to read next; in favor of having everything scheduled by the algo.
I go through about 800-1000 items in my RSS feeds once a day, save them into read it later/polar/bookmarks, and once a week, I throw the ones that still seem interesting into Supermemo.
I probably spend 30min to an hour going through everything once a day, and another hour or so on Supermemo. Most of the items in my RSS feeds are admittedly junk around 95-98% or so (HN and HN comments, reddit rss feeds and comments, lobste.rs and comments, some news sites, a few personal blogs, and some forums), but I do get a few gems throughout the week.
The newer Supermemo algorithm also tolerates breaks better than Anki (the last time I checked). So, for example, not using Supermemo while on holiday isn't an issue.
I also keep aha moments from programming and some documentation in there as well.
Edit:
Here's a demo of incremental reading in Supermemo. He marks up articles much more than I typically do. There's a lot of features and functionality in the program.