You really raise a good question here: What IS "good content?" I try to answer the same thing, on a regular basis.
Subjective, for sure. Let's start with something being the author's own idea. Simply regurgitating what someone else has already said-- without adding your own angle— is boring. "Naked" (meaning without any story) photos, videos and especially memes are just not quality content in my book.
Of course, then some people get distressed because people buy self-upvotes on lousy content and others "But look, it's working for THEM!" But it really isn't working because the moment those people STOP buying votes, their content is worth zero.