Why is copper used for that?

It would be like the weatherman playing the game of pretending the weather will be dry so when he goes to the shop there are still umbrellas in stock for him and the various other weathermen to buy. Then as soon as supply of umbrellas is not the pressing issue the weatherman admits it’s actually raining.

At some point early on the guidance itself was untruthful. The public were being told that masks were not effective while various hospitals were buying and using them.