I guess you’re right that I could group all my tags under one folder and use that to turn everything on and off in one go. And if you could have more than one level of nesting, that would be a realistic option. But I wouldn’t want to use up all my folder options just for that one task. In your example, you didn’t turn all tags off I noticed.
To expand on that, I mainly use All Off to check that I don’t have any loose geometry left ungrouped. So I just want a quick and dirty way to do that without laboriously selecting a long list. And then to toggle and return to All On just as quickly. At present, I have two ways to do that. One is to set up a scene with all tags set to off. The problem with that is that, as you add tags, you have to remember to go back into the scene and turn the new tag off. The other way is to select the whole list of tags in the dialog box and hit the eye icon.
I know I am suggesting a very small degree of improvement but it is a facility that is commonly found elsewhere so you could argue that it might be expected.