Well this is discouraging. The Russians per the NYT are closing in on Bakhmut.
I think I get Putin's end game and strategy. He wants to snatch everything where at least a substantial minority of the population do not, even now, hate what Putin is doing. It is rust belt places sort of like Youngstown Ohio on steroids where whatever remnants of the educated middle class are mostly long gone, and people remember the "good old days" of plants humming during the era of the Soviet empire.
Support for Russia is not based on the lack of ‘educated middle class’ (when did such people live in Bakhmut?) or the deindustrialisation of eastern Ukraine*, it’s based on the non-insignificant Russian minorities. Case in point, Bakhmut is 28% Russian by ethnicity and 62% Russian by language. Whatever proportion of these groups that still back Russia are doing so based on identity, not because they are ‘left behind’.
*There is a decent correlation between Russian ethnic/speaking populations and industrialisation/urbanisation in eastern Ukraine as Russian workers moved in large numbers to work in industrial jobs, but I’ve not seen any evidence that economic nostalgia divorced from Russian identity is a significant explanatory factor.