FWIW, Mandarin is not the universal spoken language of China. It's just the lingua franca of China as the region. They actually have something like a dozen major groups of dialects with varying degrees of mutual intelligibility.

The place read as Shang-hai in Mandarin is apparently read Zan-he in the local "dialect" spoken there. I think one could say Koln and Cologne sound closer together.

Did anyone say that Mandarin is the "universal spoken language" of China? IIRC, >90% of Chinese people speak Mandarin as either a 1st or 2nd language.

I don't think as many did 20 years ago, but China is consciously Mandarinizing, and English has lost its spot as the standard second language with the vastly increasing hostility from the West.