I think it reflects the harsh realities of the climate at the top of the world and the relative economic development. Many have commented about the sparse landscape. It's a very high elevation region, where some people who are not well adapted to the low oxygen in the high elevation can have aggravated medical problems. Also, the level of entertainment and urbanization is lower than in other parts of China. I think it's a preference for some to spend some of their time in places like Chengdu.
On November 17th, 2020. See this statement in context.