And likely even a Pi4 couldn't take full advantage of an NVME drive except in specific workloads or setups. I'd use a SATA M.2 if needed to save 40% of the cost on the same size SSD. Or just a random thumb drive I have around.

The Pi4 compute unit has a PCIe x1 slot, I think, and that could better put an NVME drive to use. But at that cost, for the drive and Pi, I don't see it being widely used outside of hobby or home use.

I'm excited about this and how the official Pi4 firmware now supports USB boot. Maybe if you used the Pi to run a NAS and wanted the NVME drive as accelerated cache (it can do H.265, 4kp60 decode, and H.264)?

But can a Pi even process an NVME drives bandwidth via it's CPU/etc or Gigabit Ethernet/USB 3.0/GPIO add on?

Edit: This guide is basically 1. Put SSD in adapter and 2. Set up USB boot then clone SD card to SSD. How is this article not just a forum post like the dozens of others that provide the same information and process?