That's true, but this is actually normal behavior in the instagram world since it doesn't have the concept of share/retweet. So you screenshot or use some app (ie regram) that re-posts someone's content and credits the original user.

Instagram is full of multi-million follower accounts doing this, it's very much an accepted practice on the platform. If FB wanted to disincentivize this they would, but they haven't.

Look at @lmao or any other "meme account".