Wouldn't Beijing Opera and the like be completely extinct in a few more decades

You're overthinking it, that's impossible.

But the number of similar operas may slowly decrease and merge, but it's impossible for them to disappear completely.

Quite a few Chinese operas are actually only a little bit different, such as dialects and certain dresses. Peking Opera is of course an amalgamation of the latter, with its own innovations as well as features inherited from other local theaters.

All in all, the complete disappearance, you can put 10,000 heart, that is impossible, after all, the Chinese nation is a melting pot, anything can come in the fusion. Chinese history records two of the greatest ethnic fusions, one between the Warring States period of the Eastern Zhou Dynasty and the early Han Dynasty. The first was from the Wei, Jin, North and South Dynasties to the Sui and Tang dynasties. Later on, there were the Ming and Qing dynasties, when the four ethnic groups of Han, Mongol, Tibet and Manchuria exchanged and merged. In general, the theater culture also has this characteristic.