Why is the mobile phone so popular, but the landline has not been eliminated?

Mobile phones are not only particularly dependent on electricity, but also more expensive than fixed telephones. For example, smart phones such as Apple and Samsung often cost more than 5,000 yuan. In this respect, the machine cost of landline is generally lower than that of smartphone. At the same time, for many companies, the landline number is relatively simple and easy to remember, so it is generally necessary to install a landline. Moreover, compared with mobile phones, landline phones can be used together with fax machines, which is a function that mobile phones do not have for the time being. Finally, generally speaking, although with the continuous development of science and technology industry, many new products are beginning to replace the old ones. But as far as landlines are concerned, there are still many usage scenarios compared with smart phones, because there are many competitive advantages. At this point, just like WeChat and QQ have become very popular, but SMS still has many irreplaceable functions.