That Putin has personal investment in this is not under question. I agree, there are things that he won't compromise on.

Does this mean the war continues till he dies? We could yet wait a long time.

Say he does fall over tomorrow, there's no guarantee what comes next is any better. Defeat in WWI brought about Nazi Germany. A Marshal Plan would more likely come from China.

He's had attempts on his life made. Do you think Russia will fall over if that's successful? Look at what's happened with Iran. Would Russia believe he had a heart attack if he had one?

It would be in everyone's best interests if this war was frozen exactly where it is, now. A continued war in Europe is bad for everyone, and could get much worse.