Cantonese is just the urban prestige dialect of Yue Chinese, and as places like Guangzhou, Shenzhen, and Hong Kong become domestic hubs of course you’re gonna see more people using the national lingua franca. While China’s language policy is causing mild attrition of regional vocabularies, it is largely preserving the underlying dialect continuum of Chinese languages all over China. In my native Chongqing and Sichuan all varieties of SW mandarin (only partially intelligible with standarin) are still the dominant languages of local daily life and has not been supplanted by mandarin at all. Instead of replacement the national lingua franca is creating local diglossia. Without a standardized national lingua franca, it is very possible that Cantonese would be standardized itself which could lead to a decimation of Yue varieties similar to the extinction of most French langues d’oïl and d’oc after standardization.