Probably true. But there's no situation in which Russia ends up richer for having gone to war than had they not bothered in the first place. Which is to say, everyone has lost already. It's a tragedy for all parties -- and it's Putin's fault.
If they manage to capture the coast including Odessa and the Donbass, they will have recovered a large chunk of the Russian speaking population lost after the dissolution of the Soviet Union and add a lot of industrial capacity. Long term this would benefit Russia, Ukraine would be reduced to a rump state.
But yeah the pre-2014 situation would be vastly better for all sides involved. Ukraine could have taken the Belarussian or Khazak trajectory.
While Donbas has historically been an important mining and industrial region, I've read that it has been in steep decline for many years. Due to low productivity of the industries and the high cost of services for the aging population, it is seen as a net economic loss for whoever takes it. I've read speculation that this is one reason why the Kremlin resisted annexing Donbas for so long. (There were initiatives from Donbas to get annexed the way Crimea was, because they were tired of being in legal limbo, but the Kremlin refused.)
Probably true. But there's no situation in which Russia ends up richer for having gone to war than had they not bothered in the first place. Which is to say, everyone has lost already. It's a tragedy for all parties -- and it's Putin's fault.