I read somewhere that the brewer of the Corona beer has suffered a drop in sales because of the pandemic. That should tell enough about the rationality of the consumer.
Speaking of rational consumers, deflation is seen as a bad thing in modern monetary theory. In a deflationary spiral consumers who realize prices are dropping, put off buying big ticket items leading to a fall in aggregate demand, leading to job losses and consumers starting to put money away in case they lose their jobs, which in turn leads to aggregate demand diminishing further etc etc. The deflationary spiral is a hypothesis but there is no scientific evidence for it. On the contrary, if deflation were such a dangerous thing, then the strong economic growth globally during the entire 19th century begs for an explanation. Productivity growth between 1870 and 1914 when the largest economies in the west were in the gold standard was very rapid. That's when a lot infrastructure like telegraph and railway networks were built. There obviously had to be increasing demand for all the products that the expanding industries and the new transportation infrastructure was able to deliver to consumers. Also, the prices of consumer electronics have been falling for decades and yet demand for it is increasing.
It seems to me that there is no such thing as a rational consumer. The modern consumer has a very low time preference (=valuation of the future). Consumerism is all the rage in the west. Savings rates are very low. Most people in the US wouldn't be able to raise a few hundred in an emergency. I don't think it's crucially better where I live.
Excessive consumerism is psychologically destructive over the long term. The ability to put long-term needs ahead of short-term wants is a prerequisite for civilization. That psychological damage can lead to all sorts of social ills starting from a deterioration of the family.