We do not really know.
There has been so much propaganda and gaslighting from all sides that it is almost impossible to see through the fog to what is really happening in Russia or the Ukraine. Even the leadership from both sides is being conned by their own propaganda.
It is quite possible for both sides to lose.
It is very obvious that the NATO wonder weapons have not turned the tide of war and the Russian artillery and drones were way more effective than expected. Also, the Russian commanders were willing to ruthlessly expend their soldiers like ammunition, and they had a lot more of them than the Ukrainians did.
The Russians were not very good at combined force operations, else Kyiv would have fallen in the first week of the "Special Military Operation". They reverted to "grid square obliteration" using artillery followed by human wave charges for their successes. Very traditional Russian tactics. That only works when you have a lot of extra men available.
It is also obvious that many traditional tactics of war are no longer viable. All armored vehicles can be killed by cheap drones, and so can exposed infantry, or even bunkered infantry. Drones keep getting ever more deadly, and so does precision guided artillery. Manned aircraft are basically targets for missiles.
Generals still think in obsolete terms, which are the equivalent of arranging men in a battle line and having them charge into machine gun nests, as they did in World War 1. Nobody can afford the kind of slaughter that causes.
If you can see enemy forces, you can kill them. And vice-versa. There needs to be a lot of thought about new tactics and strategies to deal with that.
I believe Ukraine will fall apart by this summer as the US fails to provide economic and military support. We are simply too broke to continue. So, Russian will have their victory in Ukraine. The prize has already cost them more than it will ever be worth.
I think the ideal thing would be to have cheap, stealthy drones that can find the enemy targets and pinpoint their position, then use precision guided munitions to take them out.