[pinkmuffinere]

The parent is explaining why it’s hollow instead of being a truss. They accurately explain that the hollow tube is optimal to counter the wind loads. Your criticism is that they didn’t discuss gravity loads, but that wasn’t “in the prompt” — the gravity load doesn’t explain why they’re a hollow cylinder. There are a wealth of other irrelevant things that could be discussed, but have been neglected because they are irrelevant to the question.

Frankly your comment disappoints me. wizardOfScience gave a _great_ answer, that would make any solid mechanics professor proud.

[potato3732842]

You're strawmanning bot me and the comment I'm replying to. Whether you're using a truss design or a solid material wall what I'm saying holds true. You can't just go all in on "put the material at the perimeter" because it'll have other problem. Gravity is just one of those problems.