Tibet has an airport, so why build a railway in Tibet?

Tibet's transportation mainly depends on roads, aviation and manpower. Although there are many airports in Tibet, due to the unstable weather conditions in the plateau, problems such as flight cancellation and delay often occur, which seriously affects people's travel and material transportation. Therefore, the purpose of building Tibet Railway is to increase Tibet's transportation capacity and security, shorten the distance from the mainland and promote Tibet's economic and social development. In addition, the construction of railways can also promote exchanges and personnel exchanges between Tibet and the mainland. Although the construction of the railway needs to invest a lot of money and manpower, it will be of great significance to the development of Tibet and people's lives.