Wtf? It's a damn 85mm. It can actually penetrate
something. It also has more survivability than a 76 because of its improved armor(health?). And thanks to those two things, an 85 can reliably slug it out with other tanks while a 76 has no hope of doing so. The T34/85 is an actual useful medium tank, equivalent to a Cromwell or an Easy Eight. And the 85 does not need to flank to win its tank battles (obviously unless it's vs German heavies, in case which case EVERY Allied tank needs to flank to get any fighting chance whatsoever)
The T-34/76 is way more cost efficient
"cost efficient"? T34/76? Really
? It cant pen shit, it cant kill anything unless it goes on a suicide flanking run, and (like the others have said) it actually has worse anti-inf than an 85. Hell the T34/76 is even more useless now because of the T70, formerly a frail infantry-wipe-machine, now turned into a normal light tank. Which means the T70 is now pretty much (an only slightly worse) T34/76 that you can get way earlier (and cheaper).