Anonymous
Geodesic domes are a pain the butt to waterproof.
A simple A Frame type structure, as posted, uses sheet material without a lot of joints/seams. Rolls of tar paper, roofing material, sheet metal, etc can be used on the structure much more easily than a Geo Dome. Additionally, the Geo Dome takes significantly more labor and materials to build. This is something to consider when on a budget of money, materials, time and energy.