The Mi 6 is Xiaomi's flagship Android smartphone from 2017, which means it is just over 4 years old now. However, according to the OEM's CEO, Lei Jun, just over 2 million users still have it in their hands. This, then, might be an impressive vindication of the device's design, hardware and longevity.
https://www.notebookcheck.net/Xiaomi-s-CEO-reveals-that-over-2-million-Mi-6-units-are-still-in-use.546829.0.html