When I talked about my first experiences with mindfulness with ex T last year I told her it felt like dissociation - that I was simply pushing everything aside and pretending it didn't exist. It felt like breathing my way through the anxiety was just like ignoring it.
Now - having just amazed myself at the almost complete lack of anxiety in the immediate lead up to and in the exams themselves this week - I think who cares what the root cause of it was? I just went through a stressful situation with barely a ripple of anxiety at all. No tummy upset, no panic attack, no hyperventilating, no insomnia, no butterflies, no bathroom issues - nothing.
I amazed myself. I didn't know it was possible.

In the end I guess the symptoms of anxiety are just that - symptoms. The anxiety itself could be caused by a whole range of different issues. If mindfulness eases the symptoms of anxiety you are correct in saying that the cause of the anxiety is still there. But you can still deal with the cause of the anxiety even without experiencing the symptoms of it. Not being in an anxious state would make it easier to deal with the issues, wouldn't it?