Are you kidding me? Do you even know about Donbass even the least? Donbass or East Ukraine region is one of the most industrial regions and contains numerous corporations unparalleled to West Ukraine even closely, no wonder most of the Oligarchs are based in East Ukraine. Steel, coal, aeroplane parts, rocket parts, heavy machinery, list goes on...
The mines are in serious trouble, the industry your talking abouth is energy intensive (and the power plants are not in rebel territory) also the Donbass is a
special economic zone (SEZ). In short the region is
state sponsord. And then theirs offocurse the history from similar regions (namely North Korea, Transdniestria, Abkhazia and South Ossetia) it has never ever turned out good and has been been catastrofical bad with the exception of Abkhazia (that has the fortune to be slightly worse with no prospects of a better future). Without Ukraines money (and electricity) the region will need to find money to continue not to mention to repair all the damage whilst the people can relativly easly move towards Ukraine or Russia, that means taxes will fall income will fall further and things will turn not so bright. Russia can not provide that can't of money, all the smart people will migrate either to Ukrainia proper, Russia or the EU. And all those that will remain will be the Oliarchs and those to docile to move in a region whose economic value is hard to determine because up to 40% of it could be a shadow economy.
I do believe this post in fundamentaly true but I'm interested in your opinion (in very short terms)
1 the infrastructure is damaged (increasingly) because of the war
2 many mines are badly maintained and are partially (increasingly) flouded
3 the energy necesairy to run it's (heavy) industry does not come from the region
4 it's Special Economic Zones status doesn't provide confidence with investors (not to mention it's history of it and similar breakaway regions)
5 It will be to easy for the (smart) people living there to move to escape the hartship
6 Russia is in competition with Ukraine concerning steel and has recently (July) scrapped a duty free import from Ukrainian steel Putin also suffers a strong Russian steel loby to
protect domestic steel
7 Corruption is widespread in the region