Iran was in a de facto decade long state of war with troops, munitions, and significant capital going to theatres in Syria, Iraq, Yemen, Gaza, Lebanon, Libya, and Sudan - just like Russia has been in Ukraine.

> Putin may not lose power, but may lose ability to keep the logistics of an invasion force

That is true and highly likely, but that isn't a win either, especially if Russia changes it's tune to turning Ukraine into an economic war of attrition, which seems to be the plan given their recent pivot to targeting Ukrainian energy and industrial infrastructure.

Since Russia can't drive troops into Kyiv, they are trying to destroy Ukraine's infra to such a degree that it would require a Herculean amount of investment from European capitals, which would be difficult to fully unlock due to Ukraine not being a part of the EU and face pressure from European nations own budgets for rearmament.

A frozen conflict with much of Donetsk, Luhansk, Crimea, and large portions of Zaporizhzhia and Kherson remaining under Russian control isn't a win for Ukraine, and longer term freezes Ukraine out of the EU and NATO because conducting an election during an active war with a nation that has previously meddled in their elections is unrealistic, but the EU can't make an exception for Ukraine due to internal votes along with the precedent it sets for other EU ascension members.