Also, because brick-and-mortar stores don't raise prices (often due to price-gouging laws), people who find themselves in a store with bottled water, for exampl

Also, because brick-and-mortar stores don't raise prices (often due to price-gouging laws), people who find themselves in a store with bottled water, for example, will buy much more than they would have if the water was suddenly $50 per bottle. They buy more than they need, leaving none for people who need it just as much but showed up to the store 5 minutes later. When demand exceeds supply, there will be some mechanism by which some demand will be satisfied and other demand will not. In the case of hotels, it's price, in the case of water in an emergency, it's randomness or physical strength grabbing bottles in the grocery store, and in some cases the government steps in and starts rationing goods.