So why have we sent Ukraine 180 billion in 2 years,and they still can't push Russia out?
Numerical superiority accounts for a WHOLE lot. First, the initial attack was somewhat successful depriving Ukraine of some troops and equipment and prepared positions. The Russian army as a whole is far, far, larger. One thousand Russians die in Ukraine, 1000 troops can come in to replace them very easily. One thousand Ukrainians die, not so much replacement. 100 Russian tanks are destroyed, 100 tanks are brought back in service. One hundred Ukrainian tanks blow up, well, too bad.
Next up the Ukrainian army was taught to fight using Russian equipment and Russian strategy. American equipment is built for American strategy and tactics. First and foremost, we ALWAYS expect to have air superiority. Ukraine cannot possibly get that.
Next up, we slow walked material to Ukraine. We didn't send them F16s or M1s until recently. And while there is a cost to sending all that we have sent, mostly what we are sending is equipment we are scrapping. So while it may have a book value of X, if we are going to scrap its real value is far less. So when we say we sent them $180 billion, that isn't really a true picture.
The Germans found out in WWII what numerical superiority does. The Soviets just ground down the Wehrmacht until it was a hollow shell. Then they launched Operation Bagration and destroyed that shell.
When Russia's initial invasion failed and the lightning war became a pipe dream, Russia went back to her tried and true self. They are just trying to grind Ukraine down.