As someone who was there at the time I’d say A New Hope was reasonably popular with school kids. If you’d gone to see it as an adult other than escorting your children you’d have been laughed at / treated with suspicion.
The Empire Strikes Back is the first film I remember queuing round the block for, but the demographic of that queue again was 100% that of a kids’ film. The Return of the Jedi being a bit of a damp squib probably would have finished the franchise as an artistic endeavour, barring the ongoing popularity of the toys. EVERYONE collected the action figures.
It was only when that generation grew up and got the money to start collecting them again that interest was rekindled, the films were remastered, the new films were made and for me it was only then that people started to apply some sort of adult intent to the first three retrospectively.
Edit - just to add The Empire Strikes Back was taken a bit more seriously at the time, but only in a ‘surprisingly good for a kids’ film’ way