Prometheus did better because it was better, fresher, and had broader appeal.
Covenant is ranking because fewer people want to see an Alien sequel than a standalone SciFi epic by Ridley Scott. Scott should have done Prometheus 2, or The Forever War, or even Blade Runner 2049. Another Alien movie is something that only hardcore Alien fans wanted,the same vocal minority that is trying to skew reality by spamming the internet with their impressions that Prometheus was a bad film that nobody liked. Fox should not listen to the Alien fans any more. There is no gain for them to make the effort. Tom Rothman, Damon Lindelof, andScott were right to take Prometheus in a new direction. They would have saved the franchise if they had continued. Fox effed this up.