Russia has NOT crushed a much smaller Ukraine in 6 months and is itself a much diminished power in the eyes of the world. They are having trouble recruiting replacements for their weakened army and have lost much of their first line equipment. Only way for Russia to win is the if they resort to nuclear weapons and that’s never going to happen! Putin would be assassinated if he even suggested it.
Russia invaded Ukraine with less than 200k troops, and since they have not taken the whole of Ukraine, you deem them a paper tiger? Militarily that does not make much sense.
I will say this, what they have taken thus far is probably nearing the extent of what is possible with such a small amount of troops.
To me the numbers russia invaded with do not indicate a goal of taking all of Ukraine. Heck there are multiple cities in Ukraine that tactically would take more troops to secure. Honestly, I believe had Ukraine had better leadership the map would look a bit different than we see today.