Nilfs baseline (write throughput especially) is slow as shit compared to other filesystems including f2fs. So just because you have this feature that doesn’t make it even slower isn’t that interesting - you pay for it one way or the other.
For many users filesystem speed of your home directory is completely irrelevant unless you run on a Raspberry Pi using SD cards. You just don't notice it.
Of course if you haver server handling let's say video files things will be very different. And there are some users who process huge amounts of data.
I run 2 lvm snapshots (daily and weekly) on my home partition for years. Write performance is abysmal if you measure it, but you don't note it in daily development work.
What is the basis for comparison? Sounds like a pretty meaningless statement at its face.