Bakhmut is only worth holding so long as UKR gets a good K:D ratio there to bleed out and weaken the Russians to soften them for a later offensive.

Unfortunately because both sides have already committed to it for so long, UKR put itself in the position where retreating to more defensible lines further back would be seen as a significant defeat similar to Lysychansk, but the Russians would harp on it far more since it's the only crumb they've gotten since Lysychansk 9 months ago.

I agree that it appears that Russia ran out of juice before it could finish the job.