Why can't Fujian people pronounce H and F clearly?

H and f are bruises, bruises, bruises. In class, the Chinese teacher told a joke about Hu Jianren. A Fujian man went to another province, and people said where are you from? Fujian people say the guess at the beginning of H, and men say Hunan? Hubei? Fujian people say it's not Hu Jian.

I'm happy to answer your question. Please adopt them.