Dark Phoenix has a lot of things working against it. Between Avengers Endgame, Toy Story 4, and Godzilla, it's got a lot of competition.
That said, if it's good, word of mouth will help. It always does. That's how movies like Aquaman can make only $72 million opening weekend, but go onto make $1 billion worldwide. Now, I doubt Dark Phoenix will gross that much. It probably won't even gross as much as DOFP at this point. But if it's good and generates some buzz, it will show in its total.