Why are most traditional Chinese musical instruments made of wood?

I think it is because the ancient metallurgical technology is not advanced enough. Bronze is not as good as musical instruments ... Of course, China's wooden, bamboo and ceramic musical instruments are all very individual, which well reflects the aesthetic concepts and cultural traditions of China people. These musical instruments are all from nature, and the masters are hermits in the mountains, which have subtle connections. Just an erhu, the speaker is made of rosewood, the strings are made of sheep intestines, the bow is made of ponytail, and the mask is made of python skin, all from nature. . . .