Why do some 'ultralight' tents weigh so much more than others?

Materials and construction drive most of the difference. Dyneema and silnylon trekking-pole shelters skip heavy poles and use thinner fabrics, while freestanding tents with aluminum pole frames and full double-wall builds weigh more but pitch faster and stand on their own. Larger 2P-to-4P convertible models also carry more fabric weight.