It's cheap (unlike NTP in a non-internet-connected device and a custom radio circuit), works anywhere where a mains-connected device works (unlike the radio stu

It's cheap (unlike NTP in a non-internet-connected device and a custom radio circuit), works anywhere where a mains-connected device works (unlike the radio stuff which may not work in a basement/concrete building, or if exported to a different country on the same grid), is unlikely to stop working in the next decade, and is more accurate than quartz over the long term due to the compensation games utilities play.