Yes, best and not at all unthinkable outcome here is a total deconstruction of the Russian mafia state and return the soil to its people.
The best, I guess, but doesn't seem that likely. I struggle to see _any_ possible upside or good outcome, for anyone, really.
Firstly, it seems like things are not going to plan for the Russians. That's a good thing, but it seems like it increases the chances they will resort to brute force and hence kill large numbers of civilians. Which will in turn create more pressure on "the West" to "do something". Which in turn increases the risk of some accidental escalation.
Then, even in the best-possible scenario, where it leads to Putin being overthrown by his own people (whether a 'palace coup' or a popular revolt), it still seems quite possible what comes after will be even worse. Either a failed state or another despot. That seems to be the pattern with Russia. Yet another humiliating defeat probably won't improve the politics of that country. Somehow it needs to be 'bought in' from the cold, and made 'normal'.