Another use case: when you look at activities that flow across multiple devices and you're correlating the sequence of events, having every device set to the exact same, ideally correct time makes correlation of events less confusing.
It's for making your computers clocks be very, very close to each other. Not milliseconds close, but nano seconds. That is more important than one might think, especially for networks.
I'm going to have something similar at home at some point, just need to make a few more cable runs so one GPS can see the sky (= more accurate)
Its cool. Imagine being able to get data from 12 satellites at the same time to get super accurate time, with a $10 GPS board. What a time to be alive!
I'm trying to reduce the amount of stuff I'm relying on the internet for. Time is pretty important, and having a local server solves all that.