On Mariupol... it seems that Putin could enter the city. The obvious problem is that there is no longer a city in there, he has conquered a flat plain full of rubble, dead and hungry people. He has simply flattened it and that only leaves ill will and hate. I guess that is not an immediate problem for Putin, yet controlling a territory that is hostile is a costly effort, so this "victory" may become his new Afghanistan, but hey, feel free to consider it a victory if it happens.
The occupation of Ukraine is not the purpose of the special operation. Ukraine will lose its army and ultra-right nationalists, just as it has already lost Crimea, Donbass and Lugansk. And then he will begin to build a new peaceful life, while maintaining neutrality and loyalty to Russia. Because the blood ties between our peoples are stronger than the current ideological differences.