we have 8 to 10% ethanol in our fuel. Running carbs dry will cause the diaphragms to harden. I have no problems at all if I just put the plane away without running the carb dry.
OTOH, when I tested a Chinese import engine, the carb went bad in a few runs. Certainly old walbro stock diaphragms. Replaced them and saw no more problems.
I do believe, that worldwide the fuel can, and will have more influence on the carb parts than the fuel companies care to admit. I am happy to live in Europe, where good ingredient limits are installed, and low quality fuel is no longer available. Don't blame the 10% ethanol. Your carb is up to that task.