That's not a problem with NFS, that's a fundamental issue with computers. Things fail. Nothing protects you from losing data, your local log-structured filing systems won't save you either. They'll help you protect an existing state from corruption, but they don't protect you from loss.

That new request you just received when a hardware failure occurred? Say goodbye to it, you've no way of ensuring it will make it to storage when the disks have caught fire. Later on, when you've put out the blaze, all that algorithms can do is tell you when things started to get lost.