The game wants us to see Oasis Landing as good, but there are some details that only make sense if we look into very dark implications.

First, all neighborhoods take you to the same Oasis Landing future. This implies no other city in the future has a time machine, and given how populated cities like Bridgeport are, this can be interpreted as some major climate event turning all the other cities into wasteland.

Second, Oasis Landing is lacking in infrastructure like schools and grocery stores. This implies a low enough birth rate and population that these things are not worth maintaining. The player will always have descendants in Oasis Landing which means at some point in history, these descendants had to flee whatever home city they lived in and move here. Likely due to most of the world becoming wasteland and OL somehow being habitable. Otherwise, why would they have descendants in OL regardless of their home neighborhood? Dystopian future is triggered by trash talking the environment, which implies climate change is the cause of it.

Third, the existence of plumbots combined with the lack of humans implies the robots were made as a necessity due to a shortage of human labor. Despite not having a school or grocery store, there exists a plumbot shop. They are also made to fight in an arena which can have dark implications since there is a sentience chip in the game as well.

Fourth, wealth inequality exists with many of the nicer futuristic houses existing in neighborhoods along poorer ones, or even a guy living in a shack in the wasteland.

Oasis Landing appears to be a very stratified city. I thought about this because I wanted to make a modern day Oasis landing with shanty towns in the wastes, gay bars, human rights museums, and perhaps even an entire neighborhood of occults/aliens that mysteriously doesn't make it into the future. Call me cynical or pessimistic if you want, but I am confident in my theory that OL is a very dark future for humanity whether the sims developers meant it to be or not.