I do find the “nothing changes, no one grows” message contradictory, but I believe that was the intention.
Some things don’t change. Laszlo’s been working on his monster for decades, the Guide doesn’t get to sing along at end, Nandor has ridiculous plans that are going to end up with Guillermo doing all of the work, Guillermo is still a black sheep.
Except they do change, Laszlo does end up finishing his monster. The guide isn’t allowed to sing, but she’s still there, casually hanging out with the vamily. Nandor builds the lair himself, with no complaints. Guillermo is still a black sheep and no one understands him but they also try because he’s their black sheep and they may not get why he’s so sad about the documentary ending but they’re trying their best to make him feel better.
Nothing changes, except when it does. No one grows, except sometimes they do.