Tiger was capable of beating IS-2 even before armor nerf and was much more oppressive against infantry with longer base range, faster RoF and scatter reduction vet on top of already low scatter and large AoE.
Tiger was dominant, because it was batshit insane.
All of those are correct I agree. But they are not giving the full picture because this is simply a 1v1 comparison and not a faction comparison. Both OKW and OST has nothing better than their AT guns to counter the IS-2 compared to super effective SU-85. Thus even Tiger was better on paper it was overshadowed by IS-2 IMO.
(I know StuG and JP4 exists but they either lack the range or penetration or both)