From that article, it looks like perhaps the difference is that snaps are isolated at the app level, whereas qubes is a layer down, where each qube is a kind of workspace with multiple apps potentially installed in it. That seems reasonable enough, though you do have to be willing to pay the disk and mental overhead cost associated with setting up the same tools multiple times, or maintain playbooks/whatever to automate that, or am I going to figure out how to get my one VSCode instance access to the different isolated environments where I need an editor, and if I do that have I basically compromised the whole system model.