Since you ask, my assumptions.
1. These systems are designed to deal with a specific threat and they are very costly. They are selectively employed and not used to shoot down any trash flying around somewhere. A low flying POS drone worth a few thousand is not the type of target a Patriot engages even if this is heading on oneself.
2. Even if you hit something, it’s going to rain down, and in some cases the warhead might even go boom, albeit not on its intended high value target.
3. Air and missile defense is layered and integrated to where you have all these various systems working together.
Ukraine has pieces here and there and not all the parts, an assortment of Euro, US and Soviet systems, being operated in part by folks that received a crash course by us, with a limited supply... All of these advanced systems work best when they are part of a complete package where various parts compliment each other.
That’s why the US M1 or German Leo is going to not really make a difference. What makes a US M1 so bad ass is when it’s with an M2, infantry, supported with AH64, arty, combat engineers, ADA, etc. It’s when all the pieces come together when you get something really beautiful happening. Just drive an M1 through the country side like a clown, and it’ll get turned into a >$10,000,000 piece of burning metal by a $1000 IED or RPG... And that’s what is going to happen in Ukraine.
This war is designed to (maybe with our own consent, or maybe by tricking our retarded naive foolish current administration) cripple our supplies, bankrupt us eve further, weaken us on the world stage, and to demonstrate why joining the BRICS nations will be the smart choice for the 21st century.