You pretty much got the essence, or one of them, of mixed media art. To many people it is soul-finding, by writing words, truths on the painting, maybe after a meditation and then covering it up but - they know it is there. That can be quite powerful.
I haven't really thought about the damaging aspect - thankfully - but you are right, if something were to happen the picture could be restored (after possibly revealing secrets 😀).
Thank you so much, makes me very happy that you like it!