Both shows had the same amount of main characters and same amount of episodes in those seasons. What is VOYAGER's excuse?
They didn't have a pre-built Setting with the politics already established, relations already established and a premise that allowed them to stay in one place long enough to build up anything that big.
Anytime Voyager stayed in one area long enough to try and flesh it out, they got complaints that they were staying in the area too long and it was too unbelievable that they kept interacting with the same aliens for more than 1 episode.