We've been hearing the "Russia is on the verge of collapse" narrative for years.

If you tell a lie often enough it becomes the truth ?

Russian propaganda have being doing variants of this dance for years with the intent to weaken the western resolve to stick to sanctions. It has invariably been Russian aligned sources that have pushed the "russia is about to collapse" as a strawman to then knock down.

The point of sanctions is to weaken Russian capability. It's never been a position of the West that it will cause Russian economic collapse, although that is in fact now the direction of travel that has become apparent lately, it's not something that is a goal (in fact the US went to a lot of trouble to hamstring Ukraine to try and prevent it in the Biden years).

Whether Russia will collapse economically is simply one of the many options you chose to ignore to further your narrative. It could, plausibly, happen, although it is not certain, but nor are any of the options you tabled.

What we do have very very clear evidence on, is that Russia (post USSR) breaks every treaty it makes with Ukraine, so the option of a negotiated peace has to be off the table as it is a near certainty they will break it (please don't give me the battered spouse "this time it will be different" response).