I can’t say for the 70s and early 80s, but during the late 80s and until 97, Star Wars was just… there. Three highly regarded films that people loved, but that’s about it.
I would even say that Star Wars kinda stagnated in the 90s. There were video games and novels, but they were really only for fans.
The Special Editions pumped life into it and then the prequels ignited the super franchise fire that we have today.
I also think that because people who grew up on the films are now adults has a lot to do with the superfandom it has today. They’re buying tickets and making their kids watch these movies who want to buy toys and dress up for Halloween…rince, repeat.