There are numerous studies proving than general happiness and life expectancy depend on personal income. That’s true, after certain level of income the dependency fades, in US its around 70k$ per year, in Russia I would say it’s 30k$ per year. But below these amounts the relation is direct.
The general poorness in Russia is the reason why going to war is fully voluntary (unlike in the Ukraine, where men are being catched at street like a stray dogs).
For many people 10-20k$ payment on signing contract and 2.5-3.5k$ monthly is the only way out of poor life, that’s why Russia do not have problems with drafting new soldiers without general mobilization.