1. Facebook's algorithms determine who sees what you post.

2. I've noticed that personal pictures get a flood of likes, no matter how trite. Widespread distribution by the algorithm + people like them.

3. Making my own post with multiple links as sources = basically invisible, compared to "sharing" similar content which is already going around Facebook.

Sometimes, of course, it's hard to discriminate between "what the algorithm doesn't like," and "what people just aren't interested in."