It's just connected. People can't go on holiday because of the Koron nonsense, and can only stay at home and play video games. With the money they have left over, they buy hardware. And suddenly everything is just sold out immediately.
That is certainly one reason. But mainly the manufacturers had to decide on the amount of products they produced a few months ago. At that time it looked like the focus of most of them was on new gaming hardware.
So less was produced so that the manufacturers would not be left sitting on the products.
Now it takes a few months until production is fully ramped up and the products reach us.