Ukraine is being attacked and they are extremely tough, otherwise the war would be over by now, they also don’t have the military capability to win the war, continued fighting will do nothing but sacrifice thousands of Ukrainians for a war they cannot win.
Ukraine is roughly similar to Japan in WW II, they clearly were being attacked and closed in on, they continued to fight in a war they could not win, until we nuked them, which was the right move at the time.
In Ukraine, one side has a complete military with 10s of thousands more men against the other side that has next to nothing.
The advanced weapons systems and air assets Ukraine would need to have a chance to win the war are not there and will not be there for months if not years, in the meantime Ukrainians by the thousands are being killed.
As are Russians.