It certainly isn't faster or more reliable for a single node, but this is just homelab stuff. Nothing in mine is particularly necessary. I think it's interesting because it's now accessible and receiving support from multiple vendors.
At some scale, it's nice to separate the two. You don't care much about where the disks live vs. where your compute is running. You can evict work from a node, have it reschedule, and not have to worry about replicating the data to another machine with excess capacity. Though I'm no authority on this topic.
If you want a whole drive, sure. But if you want to virtualize storage (e.g. split up one drive) you need a network protocol.
Why is this better than just connecting the drive via PCIe bus directly to the CPU?