I think this is just false - wealth held in assets can just disappear. If my stock portfolio is worth £1m, and then the market crashes so it's now worth £500k, that difference in implied value hasn't been transferred from me to someone else, it's just gone, sadly.
To take a super simple example... let's say I'm a famous artist and I paint a new picture. My last painting sold for £100k and this one is valued at the same price by art collectors. The painting is worth £100k. Now, a little while later, it turns out that I'm somehow a fraud and no one likes my paintings any more (
). No one will buy my painting. It is worth zero. Value/wealth was created when I painted the painting, and destroyed later on when new information was revealed.
Similarly, if a tornado destroys your house, it hasn't transferred the value of your home to someone else, it's destroyed it. Now, instead of a tornado imagine a pandemic, and instead of a house imagine the whole economy.