The recommended reference reasons are as follows:

(1) environment: among the four listed cities, Suzhou is the city with the fastest development of industry and city circle at present, because of its large financial investment, it has good background resources in various hardware facilities; Suzhou, an antique part of the old resources, has not been invaded by large-scale wars in past dynasties, and its ancient buildings and folk culture have been well protected. At present, it is also one of the few original ecological tourist cities in China. Chengdu and Chongqing have always belonged to the land of abundance. In recent years, industry and tourism have developed rapidly. However, due to the baptism of war, the city has no fixed symbolic culture, and the beautiful environment can only be piled up by the acquired capital. Without the wisdom of the predecessors, the integrated urban environment seems a little stiff and featureless. Next, let's talk about Kunming. Kunming is a place where the seasons are like spring all over the country. It has no serious industrial atmosphere. There are also many expenses for urban hardware renovation based on tourism revenue, but the rare air quality and traffic environment rank first in Kunming.

(2) Climate: Among the four cities, Kunming is the only one close to the tropics, and there is no obvious distinction between the four seasons. Su Chengyu belongs to a city with the same latitude, and the details of the four seasons' climate contrast are the same as those of Wu Hanyou with the same latitude. It is extremely hot in summer and extremely cold in winter. Therefore, based on the climate alone, the characteristics of spring-like seasons in Kunming should be particularly suitable for the elderly to live and support the elderly;

(3) Cost: Among the four cities, Suzhou is one of the fastest growing cities, followed by Chongqing and Chengdu. Large-scale investment to attract talents indirectly stimulates all kinds of consumption cost, especially the key cost of providing for the elderly. The investment in public transportation and other basic welfare facilities in the four major cities makes it no problem to travel now. However, with the expansion of the city scale and the rapid expansion of the population, no amount of welfare investment can solve the traffic congestion problems in Chongqing, Chengdu and Suzhou, and Kunming has no obvious population agglomeration effect at present. Among the four cities, the cost of providing for the aged is the lowest for a long time to come.

Above, my humble opinion, for reference!