Is there any non-airgapped use case that doesn't require authentication?
NFS sounds great when presented as a "faster alternative to samba". As soon as anything else is said about it you realize there's a reason it's been a bad choice for 20 years.
> Is there any non-airgapped use case that doesn't require authentication?
Here's one: Say you maintain the devices in your home LAN/WLAN, and you would like to centralize the storage/access of certain data like photos, music, video, shared Keepass DB files, etc. Let's also assume that you don't have a local threat model in your home network that includes "highly technical people that know about setting their UID who wish to access files you don't want them to see or have write access to". I would argue this is a semi-common home scenario for many of us. Perhaps you want your SO and/or child to have access to shared files on a NAS which supports NFS, and you don't have any Windows endpoints to worry about.
In this scenario it's perfectly fine to just setup the devices which you want to have access to the NFS share(s) and completely ignore authentication for the file sharing protocol. If you're worried about WiFi guests that might be savvy or curious then simply create a guest-only wireless network that can get out to the internet but not the LAN.
NFS sounds great when presented as a "faster alternative to samba". As soon as anything else is said about it you realize there's a reason it's been a bad choice for 20 years.