It's not. The exact same reason why NFTs are able to appreciate so much in value over a short period of time means that the entire market can silently crash overnight as well.
If these wash traders stop pumping up prices all of a sudden, you could price your NFTs at sky high values and no one will bat an eye at you.
But this is not true in the case of NFTs, if a NFT sells for a high price that does not mean the NFT you are holding will do the same, since they are not fungible no one knows the true value of what they are selling and buying and each person is using their best judgment in order to try to figure this out, but as soon as new money runs out then the majority of those coins will crash in price almost immediately, but most will not notice and they will only do so once they try to sell and there is no one there to buy at any price.