OS level checks will inevitably work differently on different OSes and different versions. Having a check like this in the app binary itself means you can have a standard implementation regardless of the OS running the app.
I often hear similar arguments for or against database level security rules. Row level security, for example, is a really powerful feature and in my opinion is worth using when you can. Using RLS doesn't mean you skip checking authorization rules at the API level though, you check on author in your business logic _and_ in the database.
OK, I'll bite. Do you think Node.js implementation is aware of DNS search path? (My guess would be that it's unaware with 90% certainty).
If you don't know what DNS search path is, here's my informal explanation: your application may request to connect to foo.bar.com or to bar.com, and if your /etc/resolv.conf contains "search foo", then these two requests are the same request.
This is an important feature of corporate networks because it allows macro administrative actions, temporary failover solutions etc. But, if a program is configured with Node.js without understanding this feature, none of these operations will be possible.
From my perspective, as someone who has to perform ops / administrative tasks, I would hate it if someone used these Node.js features. They would get in the way and cause problems because they are toys, not a real thing. Application cannot deal with DNS in a non-toy way. It's the task for the system.
Oh I'd be very surprised if Node's implementation would handle such situations.
I also wouldn't really expect it to though, that depends heavily on the environment the app is run in, and if the deployment environment intentionally includes resolv.conf or similar I'd expect the developer(s) to either use a more elegant solution or configure Node to expect those resolutions.
Then you are sort of saying: I expect Node.js implementation to be bad... why do you need a bad solution if a good one is within hand's reach?
In other words: Node.js doesn't do anything better, but, actually does some things worse. No advantages, only disadvantages... then why use it?