It's interesting.
Jason Momoa ain't a box office draw (double plastic status) however he was still a relatively young brotha (37 at the time) and i recall during the Aquaman campaign many females were gushing over him. That and while the general public maybe didn't care for "Aquaman", i think Momoa as "Aquabro" + the marketing of "Atlantis" as the immersive backdrop is what intrigued people about the IP.
Whereas from the first trailer of Black Adam, Rock (50) looked old. No longer the young guy that kids idolized and women wanted to throw themselves on. More like if your grumpy uncle was a roid head. That and there was nothing intriguing/innovative in the marketing of the IP.