Jurassic Park was originally intended to be written by Crichton much earlier, but delayed on the advice of his publisher. At the time, the Dinosaur Renaissance was still going strong, and Crichton was told that publishing it at the time he wanted to would mean it'd just be drowned out. Spielberg later got the rights after getting into a discussion with Crichton, who let slip that he was working on a new book with dinosaurs, and Spielberg was excited because he said he loved dinosaurs. Jurassic Park's success has very little to do with Star Wars. Maybe a little with Spielberg getting the rights, but that's very speculative. In fact, I would argue that it's the other way around. Jurassic Park laid rhe groundwork for all modern CGI. The prequels would not have been possible without Jurassic Park, and even the 1997 SE used redressed models from Jurassic Park.
In Terminator's case, Cameron claimed to have gotten the idea for it after seeing John Carpenter's Halloween (another favorite of mine) and having nightmares of an unstoppable robotic skeleton chasing a woman. With the added warning of nuclear proliferation, I could easily see Terminator having plenty of success without Star Wars.
