My knowledge of (not Russian but) post-Soviet bureaucrats comes from personal experience, I speak fluent Russian and follow their news/politics sporadically but over the past few decades. I think the way they are portrayed in Chernobyl is brilliant. It's a structure so permeated by apathy, corruption, bullying and grandstanding that it simply cannot effectively transmit information in either direction, whether top-down or bottom-up (but especially bottom up). It's clear that Putin was fed a steady diet of his own wishful thinking / propaganda, and he bought into it fully. If he had a realistic view of the world around him, he would have prepared a lot better for this war of aggression that he staked everything on.

And, as an aside, I think COVID started for the exact same reason as what's portrayed in Chernobyl. Chinese model of governance is not that different. When accurate sober assessments of facts on the ground are needed and speed is of the essence, its ineffectiveness takes over. Once the genie is out of the bottle and there's nothing to hide from superiors, and once Beijing sends over some adults to whip things into shape, the sheer scale of China's economy allows it to power through and suppress the crisis using draconian means. But for the first who knows how many weeks (certainly well before Jan 1 2020), it was much slower motion Chernobyl.

The reasons for the immediate action might be logical, but looking at the medium term consequences it breaks down completely in my mind. The only two possibilities I can see going forward is either a forever-war as in Afghanistan, or a forever-sanction situation like Iran or DPRK.

I don't see how any listed benefits would outweigh the costs of either option. It troubles me a lot, because Putin has seemed to me to be a carefully calculating player up until this. It makes me wonder if he has truly lost it. Or if there is some grand plan which this is only a small part of. Both are scary.