To be fair, even as a Soviet expat, a few weeks before the invasion I publicly wrote that I don't believe that Putin is stupid enough to invade Ukraine, because there is no possible end game in which he can win: he doesn't have the resources to hold a significant part of Ukraine.
Especially in the face of Ukrainian (and Russian, and Polish) long-standing tradition of insurgency warfare (specifically focussed on destroying enemy's logistics).
Also because in face of an invasion the potential amount of ground troops on the side of the defender becomes equal to the number of civilians above the age of 8 or so.

So while I was wrong about Putin, it wasn't impossible to call the rest of it.
The absolutely absent motivation of the Russian troops (from their perspective, they are shooting at their brothers - this is literally what they have been taught all their life), the fierce motivation of the Ukrainians - who are shooting at invaders of their home; the later radicalization of the Russian troops in the face of losses, etc. *Even without* the massive blunders, perpetually broken equipment and the centuries-old corruption of the Russian military, it was always going to end badly for the Russians.
Even if they, as some here claim, can counter the counteroffensive, there is no end game that ends with a long-term Russian occupation of Ukraine, simply because in such a case Ukraine has potentially something like 40 million combatants.

Similarly, and for the same reasons there is no end game that ends with a complete occupation of Russia (except maybe by the killer robot army that the US has just commissioned.)