Noticing trends in logs ,especially across different systems, could be useful for identifying a lot problems before they break.
For all the grief people give Datadog, it is an incredibly good product. Unfortunately, they know it, and charge accordingly.
And I’ve worked on some of the world’s largest systems and in most cases simply looking for the words: error, exception etc is enough for parsing through the logs.
For everything else you need systems like Datadog to visually show you issues e.g. service connection failures.
Node is throwing EADDRINFO. Why? Well, it's DNS likely but cause of that DNS failure is pretty varied. I've seen DNS Server is offline, firewall is blocking TCP Port 53, bad hostname in config, team took service offline and so forth.