Just a thought, one of Chinese Red Army's favorite tactics in the civil war was to feint attack on a town and ambush the reinforcement. This sort of tactics can be magnified to a larger scale today with modern ISR and air power, destroy enemy in maneuvering.
Of course if the enemy is determined to stay bunker up in the cities then you won't be able to do anything about it, but if the enemy is willing to come out to play.....The Russian may not have the man power or the air power to pull this off in the start, but I wonder if the PLA may prefer this type of method
That is a tactic suggested by some Chinese observers. But the same observers determined that the Ukrainians knew they have no chance in open space fighting the Russians, so they stay in the bunkers hoping to weaken the Russians to abandon. It is a matter of how much pain each other is able to take.
Yes the Russians can pull this off, it is their favoured options because only in the open they have the upper hand in armours, aircraft and MRLS etc.
The tactic is well known to everyone, the real challenge is to make the enemy think that they have a chance by going out to the open, or the risk of fighting in the open worth the gain, or the defeat in the open is better than starve in the bunker.
A great example is battle of Changping between Zhao and Qin in 260BC. Lots of people calling the Zhao general Zhao Kuo a moron because he went out his fortresses to fight the Qin in the open leading the defeat. But a research paper by PLA actually think that Zhao Kingdom had no chance of avoiding the defeat on strategic level because of the lack of supply and economy size. It is just matter of time, the outcome would be the same. So Zhao Kuo was forced to gamble. Lian Po who was replaced by Zhao Kuo took the opposite tactic by staying in the fortresses. He was not defeated, but he was depleting the country, so he wouldn't make it any better for the country.
Ukrainians are just doing what Lian Po did. The difference is that Zhao hand no allies then, Ukrainians "think" that west is their ally and able to pressure Russia to back down.