Russia being a poor country, won’t be able to hold on to whatever territories it captures. The long-haul says that Russia will lose any areas it takes, and eventually, even Crimea will be lost by the Russians.
Crimea and whatever else Putin takes, will become the new Afghanistan to them, where they were met by the devil.
Or perhaps it will become the new Grozny, rebuilt nicer than ever and the once defeated Chechens are now loyal Russian fighters.
It’s not really so much about poverty as it is demographics and a dwindling population.
Russia has one of the lowest birthrates in the world. The population of ethnic Russians among Russia as a country is even worse. Chechyans breed like flies, as do the various Eastern, Northern and Siberian peoples, but ethnic Russians will be replaced by other peoples by 2100.
Russia is steadily destroying its ability to even defend its own borders. It turns out that their high tech military equipment depends on parts from US and European vendors. Their tanks use French thermal sights. They use US made integrated circuits for their military electronics.
Here is an article with pictures of PC boards from Russian helicopters, missiles, and other arms full of US made integrated circuits.
As sanctions tighten the Russians won't even be able to repair their helicopters, airplanes and missiles.