i write about a product called MAAS, a bare-metal provisioning system. i have a houseful of NUCs of different vintages to provision, but sometimes i want to try odd configurations and/or create error conditions to build troubleshooting doc. LXD VMs are better for this than NUCS, because they are easier and faster to recover when things go south.

also, i use them to do large builds of code on OS versions other than the one i'm running on my laptop. and i use them to test packer-built custom versions of FreeBSD, RHEL, Alma, Rocky, etc., because i can control the interfaces and storage more easily when debugging my packer builds.