Is it conceivable to have a war that actually economically elevates a country? Yeah, maybe if you find a bunch of oil or gold. Unfortunately for the Russians, Ukraine has neither so the Russian economy will continue to tank. This is also within the context of their economy being atrocious to begin with. Putin couldn't afford a war, but presumably he could not afford Ukraine to join NATO either.
While without a doubt Russia expected to win this war under a week and now they are frustrated this is not the case I doubt that they are destroying the infrastructure out of anger, this is nothing more but another example of total war, in which the invader begins to destroy anything that may have some use for the opposite army with the hopes of demoralizing them and at the same time to cut short their supplies, this means Russia is taking more seriously the war and it is just one more indicator that tells us they are not going to back down on their decision to invade Ukraine.
Seems clear they didn't expect the type of economic blowback they received either. The annexation of Crimea was met with little to no resistance and their economy did not crumble as a result. Appears now that major companies are pulling out their operations from Russia on top of the sanctions already in place. Russia is taking civilian causalities more seriously, certainly.