It's a pattern I started long ago where I have one drive to hold OS install and program files and one drive to hold data. Bottlenecks on storage IO are less common with nvme but my recent build is a workstation that runs a bunch of VMs and also serves as a DAW. I thought it better for each drive to have its own PCIe lanes. I'm also working on a 10G LAN and didn't want a bottleneck during disk IO.
You could also have IO storms with so many VMs, what if windows update start while 10 VMs kick of Ubuntu auto updates while at the same time a DB starts a backup job? In that case I don't want my web browser to slow down.
You don't want a problem with a single drive to take away everything you have, like RAID0 does. The only good case for RAID0 is temp/buffer files that you don't cry if you lose.
Anyway non-RAIDed simple setup is also vulnerable to drive failure. So backup (and RAID1 if you need HA) is the solution, not non-RAID. RAID1 just make x2 failure rate.
Yeah, I've had bad luck with raid consumer/prosumer gaming motherboards. I do like raid on servers, my r430 cluster has PERC 730 raid cards, never had a problem.
You could also have IO storms with so many VMs, what if windows update start while 10 VMs kick of Ubuntu auto updates while at the same time a DB starts a backup job? In that case I don't want my web browser to slow down.