Let's face it: even in rich countries, price always matters. Even for the military.
Why launch 20 missiles @ $1M when you can launch 200 @ 0.1M? Sure some missiles will fail, but nobody's defenses can counter the remaining 150+ at once. This is why they have automatic guns: you point (as opposed to aim) & spray bullets. One of them eventually connects. I think the US army doctrine is on the order of 100 shots for a single hit.
They can do that because bullets don't cost $1M each. I can afford the $20 Harbor Freight tool to do a one-time job the right way because it's not the $120 pro equivalent. It'll break after I use it 5 times, but that's OK, more where that came from. And often as not the $20 tool is pretty good and does last; the $120 tool is nowhere near 6x better.
Oh, and let's not forget that even those super-pricey weapons still have duds, and anybody with an iPhone or a Toyota will tell you that civilian technology can be pretty damned reliable.
So why isn't the US military doing the equivalent of buying in bulk at Harbor Freight when appropriate, following its own doctrine of "overwhelming" force? Why does every single little thing have to be so high-grade and expensive? An Air Force officer recently was quoted "quantity has its own form of quality." I realize that carrying all that extra quantity is an issue, but these days we have machines and logistics systems for all that, even robot pack mules for the last mile.