Interesting that you think that, as much as Star Wars did kind of hurt fantasy cinema (even the Japanese were clearly effected and their output became more Hollywood-influenced) by raising the bar for SFX and by getting the studio moguls into a money crazed frenzy, it did so unintentionally.

Lucas, Spielberg and Cameron never set out to destroy fantasy cinema. Lucas was a fan of Japanese cinema and Cameron was a protegee of Roger Corman in fact, they only set out to make good movies and push cinematic art forward. Fox thought Star Wars was going to be one of the biggest flops ever and purposely released it at an "off season" to minimize its box office damage. It was the executives who became addicted to Blockbuster event film megahits once they tasted the blood that was Jaws and Star Wars who are really to blame here. They greenlit most films and do the most financing, not directors.