SUCH INANE STUPIDITY
What you fail to understand is that the Russian Army at present is fighting a war that most soldiers would prefer to avoid.
Which is why Putin is changing tactics. He now really-'n-truly wants a negotiated settlement. Which will likely include the parts of the Ukraine that speak Russian and wish to be Russian. (If that is their foolish notion of a "better life".)
And that is what is going to happen along with one more important qualification. That is, the Ukraine will ask (inevitably) and likely obtain admission to either NATO or the European Union. Which will change the complexity of the matter. Meaning this: Should the Ukraine inevitably become a member of the EU, then likely also NATO.
Which will mean (upon implementation) that a NATO nation borders on Russia. Which should upset the class of Russians presently running the country (on an historical
moneyed boondoggle).
Putin & Co are quite likely to detest such a happening. But, after all, they started this war. They could still negotiate the separation of certain parts of the Russian-speaking Ukraine. But not one kilometer more.
Moreover, why any Ukrainian would want to become a member of a Toxic-State like Russia today is beyond comprehension - but if that is what they want, then give it to them! (See map of Russian-speaking Ukraine
here.)
Such inane stoopidity deserves what it gets - a Russia run by the super-rich.
If that factor cannot spark an internal revolution in Russia then nothing can ... !