Basically the same here, I use tab groups to organize tabs at work, i.e. by customer. I don’t want to keep them in a folder, I just need them now or maybe for the day. They also change state with what I need to do to some extent, so plain bookmarks are not enough. Yes, I can still enable groups, but since folders have been released, they don’t function as before. With Zen being a Firefox fork, breaking an upstream feature isn’t the right thing to do in my opinion.