You are delusional to think that sanctions can help fight Russia.
Sanctions have worked to an extent, but I don't believe sanctions can make Russia stop the war. This looks like a war in that the ego plays a very big role. Neither Russia nor Ukraine nor NATO would want to agree that they've been defeated.
Without the sanctions, Russia would have been able to do more harm to its enemies through economic means and otherwise. At this point, they're just looking for ways to survive whatever sanction that gets thrown at them and they've been managing well so far.
Even if ruble will go to zero, Russia would still continue producing tanks and rockets and paying their military.
The ruble can't go to zero but I get your point. If the ruble goes to zero that would mean inflation will be at about 200% and no country can fight a war and win with that kind of inflation. The price of everything would be so expensive that they would be forced to turn their focus on the economy instead of war.