Were they, though? Or are you confusing a complete queue/attraction/post show integration?
People tend to get this weird misconception about EPCOT "ride length" when its not really accurate...
Spaceship Earth, Living with the Land and World of Motion were the only 10+ minute "rides". UoE was 39 minutes of preshow and stationary movie watching surrounding 6 minutes of "ride".
In 1982, Railroad, TTA, Jungle Cruise, Small World, Mission to Mars and 20k were all greater than 10 minutes, with a much greater concentration of lower time attractions.
If you are talking shows...they match up fairly evenly.
Yeah...Epcot had more long "experiences" but it did not have some epic glut of long ride experiences.