There are two things, one trivial and one non-trivial, that would vastly improve the feed for me (and I imagine for a certain cohort of which I am a member):
The trivial one: Allow me to turn off all links. All of them, globally. I don't care about the news article you just saw that reinforces your political views; I don't care about the clickbait editorial you just read; I don't even care about the moderately interesting piece you just shared because I probably already saw it on Twitter. No links. Just the pictures and status updates like before the age of inline expand.
The non-trivial one: Allow me to turn off all images with text in them. Why? Because these are, with stunningly high frequency, visual versions of the same political-view-reinforcement article links. I already know if a friend or family member identifies as a liberal or a conservative. I don't need a regular stream of smug SomeEECards or Memegenerator pictures to remind me. On the technical side, there's clearly some fuzziness, but I have to think simply detecting the presence of text would be a comparatively simple task to what else Facebook's deep learning systems do.