I can saturate both a 1 and 2.5 Gbps links with WireGuard encrypted NFSv4 on thin clients that are relatively old.

I also use it for shared storage for my cluster and NAS, and I don't think NFS itself has ever been the bottleneck.

Latency-wise, the overhead is negligible on via LAN, though can be noticeable when doing big builds or running VMs.