Also worth noting that Qubes uses VMs (Xen) with whole guest OSs as the isolation mechanism, whereas Silverblue uses containers (Flatpak) to isolate individual

Also worth noting that Qubes uses VMs (Xen) with whole guest OSs as the isolation mechanism, whereas Silverblue uses containers (Flatpak) to isolate individual apps. Qubes is great if you're paranoid and want to keep your banking VM isolated from your web browsing VM. Flatpak and Snaps are great if you just want to grab the latest LibreOffice without pulling a ton of dependencies into your package manager. I guess there's no reason you couldn't install Silverblue as a guest OS in Qubes...