Price versus average earnings
The entry-level Mate X model retails at roughly $2,500 — or nearly eight times the monthly minimum wage in Shenzhen, where the company is headquartered.
Yes, it's expensive so average earnings are not really relevant for comparison. More important are the number of people in China earning say USD 200,000 a year, that can afford such status symbols. This might only be a tiny percentage of the working population to still be a significant number of total sales. For example, assume there are around 800 million working Chinese, you're looking at around 0.25 % of these keen on having the latest shiny, shiny, ie. a high-end flagship every year, especially if it's something that other people don't have.