Of course Putin is primarily to blame for the destruction and loss of life.
But the west, especially Biden, takes a share of the blame.
At the start of the invasion Biden had two choices:
Do nothing and let Ukraine quickly have no choice but surrender. Not good but minimal damage and loss of life.

Properly arm Ukraine from the start so they could destroy Russian ships, tanks and airfields.
That would have stopped the destruction of Mariupol and other cities.

Instead Biden took a middle path. Giving the Ukrainians just enough weapons to keep fighting but not enough to stop the destruction or to beat the Russian invaders. Guaranteed to cause maximum loss of life in Ukraine