I think WB was so scared of MARVEL'S INFINITY WAR they made 2 AQUAMAN movies into one. And they're both poorly put together in a clumsy, dumb script, filled and saturated with mythology, exposition and "Booms!" interrupting dialogue scenes.
James Wan is still a terrific director that makes a terrible script to look cohesive and intelligible and with expert camera work and great fights that don't look generic, but planned and imaginative. But the result still struggles with squeezing and ocean sized mythology and a GOT sized cast (and intrigues)into one movie. And still be tainted by MARVEL's style handbook where Jason Momoa wastes his talent in imitating THOR RAGNAROK and Amber Heard carries the "woman rolling her eyes at starring" cross.
With less executives panic, AQUAMAN had everything to become a classic.