Zigong is deep in Sichuan, why is Gong dialect as unique as Mandarin?

I have asked the same question before: The cities around Zigong are all flat-tongued, why Zigong is absolutely tongue-rolled (a few words in Bazhong, Yibin Xichong and other places are tongue-rolled), and why there are "enclaves" in language. I read a lot of information and got some answers. I will now talk about two important points: 1. Academics believe that Zigong people are mostly descendants of Zhang Yimin. After the Qing government began to wipe out Zhang in A.D. 1646, Zhang's remaining descendants fled from north to south and survived after arriving in Yibin, Zigong, laying the foundation for the present Zigong dialect. 2. Businessmen from Shaanxi and Yunnan played a decisive role in Zigong dialect. Zigong has developed salt industry since ancient times, so there have been many salt merchants from other provinces in Zigong (the current Xiqin Guild Hall is one of the historical evidences). I wonder if the landlord has noticed that Yunnan dialect is very similar to Sichuan dialect, most of which are tongue-rolling, and some of them are basically the same as Zigong dialect. In other words, ancient businessmen from other provinces should have played an absolute role in the development and stereotypes of Zigong dialect! !

In addition, I reiterate: I am from Zigong, and I will always speak Zigong dialect. I am now in a foreign country, and those who are biased against our Zigong dialect will never change my determination to speak Zigong dialect! ! !