I came across this post that spoke to removing unused variables
The solution is to click on each variable to see if it is used on a page. If you have lots of variables, this can be a very tedious task.
Much like how in the Layout screen, elements have an icon to show whether they are visible/hidden, have a binding or a workflow, would it possible to add an icon next to variables to show if they are unused?
That would make the identification and deletion process so much easier.