I wonder if I should try out Illumos as I am rebuilding my home server, but I am afraid that due to lack of time, it'd take me ages to replicate my libvirt-based setup with around 30 services.

How well are Linux containers and VMs supported in Illumos? How about nested KVM? That could help with the transition as I am heavily leaning into GNU tools and KVM.

FWIW, when I first laid my eyes on a Sun workstation back in the 90s and seen the Control key where it rightly belongs (in the place of Caps Lock in broken layouts :), I said "duh" and have never moved back from remapped Caps-as-Ctrl.