What does NATS do that you think is amazing?
In this sense it's a bit like Sqlite, which also JustWorks, as opposed to something like Postgres which requires more fiddling and maintenance.
And functionally, it allowed me to create a service-bus topology where multiple processes can post messages on a set of subjects that can be subscribed by multiple other processes (think stock market quotes). This pattern is surprisingly difficult to implement in other message brokers.