You know if Back to the Future really had a materialistic message, why did they still live in the same house at the end?

I mean George is a successful science fiction writer. From a time travel perspective, it would have been believable if Marty had tried to go back to his own house, only to find out somebody else lived there and his parents lived in a much richer neighborhood.

That's kinda what happened in part 2 but obviously for the sake of movie logic and ease of wrapping up the story, they just keep the McFly's in the same house. Which is believable too. I just think Glover was reading way too much into how the end of part 1 glorified materialism. It shows that George is more successful because of his self confidence.

EDIT: I mean, do we actually know George McFly specifically makes more money as an author than he did at his previous job? Self employed authors/writers are kind of a hit and miss profession. The fact that Biff is not his boss and he is a writer is simply a better fit for George McFly, career wise. Regardless of how well either one paid.