If the opponent goes for a tank destroyer to counter it, they've invested resources and popcap into a unit that does next to no anti-infantry damage.
They can go T34/85s and mark target to dive a P4 and wreck it.
They can ram with T34/76 and instadelete with 0 effort IL2 rockets.
They can go double AT guns and a medium.
They can go Guards and double AT guns.
They can go Jackson and just hunt you down.
They can go Comet with its wonderful white phosphorus shells.
They can go Easy 8s and outduel you.
They can go M4A3:76 and hunt you down in packs with radio net.
They can go tank hunter cons/ptrs penals and supersnare you.
Meanwhile your roster has expensive engineers without flamethrower, a Panther that cannot help unless it literally 1v1s another tank, a KT that’s so slow it dies with ease and gets penned by everything thanks to power creep, a Sturmtiger that’s been nerfed to death and Obers which are super expensive and take corever to reinforce, with no AT capability whatsoever.
Aside from an open ground blob vs blob engagement, it’s hard to inflict more bleed as OKW in the late game. If LEIGs and the KT were good, this would be a different discussion.