But that's the thing: the largest thing around at that point in the game is the Luchs.
Throw the fact that the SU-76 doesn't counter the Puma on top of that, and you've got very little reason to slow your tech for it.
Once you get to the medium tank phase, you build the SU-85 instead. Given the choice between a dedicated tank destroyer that can deal with the whole enemy lineup and a dedicated tank destroyer that can't, why would you pick the SU-76?
Why would you ever pick SU-76 regardless of its state instead of 85 regardless of its state, when you can no longer combo call-in KV-1 with T3?
Giving barrage a cost instantly removed the unit from the meta, binding KV-1 to T4 was another blow.
That tells me to focus on barrage part of the unit, not AT part as its AT is sufficient.
Why would I EVER want to use SU-76 in situation where I didn't lost fuel for 10 minutes and can't build anything else at the time opponent got mediums?
SU-76 is fragile, expensive, micro heavy, little rewarding gimmick supplement unit and ALL of gimmicks it excelled at or was paired with were removed from the game.
The unit will never be alternative to SU-85 or ZiS when you are not being roflstomped, because it offers less AT and using it for accurate barrages is too risky closing in.
It doesn't have identity crisis, it doesn't have balance problem, it doesn't compete with SU-85, simply all friends it played with were forced to play with SU-85 instead with changes over the time.
For it to be used widely again or even be considered as a choice it would have to be more then weak-ass expensive ZiS-3 on tracks and I can't see that kind of rework happening to it.