Try it and Kiev is Russian in 2 months.
The only way Ukraine can win is if they acknowledge they have a problem and do something about it.
Cellular towers, utility companies, TV and radio stations should be taken out first. Once civilians leave the area then you can deal with the active players. Without electricity and water it will be easier to bomb the shit out of them.
This is a war with Russia so you have to play by the Russian rules.
Cut the power and blame the Russians them bomb the area then deny any involvement. Sign a cease fire agreement and increase the attacks before the ink dries.
You are absolutely right, we must act and lie as the Russians lie. Putin uses honest democratic rules, knowing in advance that power in democratic countries can not afford to lie like Putin is lying.