system
Given the following post, respond as if you're commenting on Reddit:
human
[Truman Show]Why did they build a giant dome which must have cost... tens of billions of dollars? Why not just build a sufficiently high wall around the perimeter which from the horizon, looks real? Why fake the sun and stars and clouds?
gpt
The creator says it. They wanted everything controlled except Truman. Not to mention the spectacle of it. The spectacle of a structure so large it can be seen from space ensures that everyone on earth will pay attention.

Truman needed to live in the most perfect place. They can't do that without total control. Overcast weather could ruin a moment they had in the plans.