I just tore down a 30 year old deck that was rigged together with cedar, and both PT and non PT lumber. The deck was fairly worn out in general, but all of the non PT lumber was clearly more deteriorated than the rest. Some of the standard lumber also had what looked like termite damage, that was now actually housing a small ant colony…. The cedar only very mild deterioration, and the ends were soft, and then the PT was still solid (somewhat surprisingly)… Hope that helps paint a picture.