There is certainly no need to have an atomic clock in each everyday device.

However, when you own one atomic clock, which you can use to calibrate all quartz resonators and many other kinds of devices used for measurement, then that is one less dependency of the outside world.

Some people like to be as independent as possible.

As long as you don't have your own atomic clock, you are dependent of Internet or other communication means and of access to institutions that do have atomic clocks, to synchronize and calibrate your devices.