A Super heavy TD can not be countered by tanks and TD well that makes sense.
But then what does counter an Elefant? It cannot be countered by T-34 or SU-85, so that leaves you with ZiS-3 and PTRS. ZiS-3 is not very mobile and would take a very long time to chip away at an Elefant, which can just drive away and get repaired. You would also have to protect them from counter-attacks, which you will have to do with zero armor support, because there is an Elefant... As for PTRS, they're not killing an Elefant any time soon.