In the grand scheme of things, the customer may have slightly more pull than the cashier ringing up their order, but it’s the CEO and the board of directors that control the narrative. That’s why we’re getting bigger and less fuel efficient vehicles, bigger and more fattening meal portions in restaurants, and bigger less affordable houses.
Other people have covered the true definition, so let me pick apart your examples.
Bigger and less fuel efficient vehicles are being produced because of fleet emission standards, as trucks and SUVS don’t count towards your “fleet” lineup. So companies are producing and pushing these hard, otherwise they will need to go mostly electric very quickly to meet emission standards. (It’s stupid I know, but blame lobbying and very old policies made to protect the American truck market).
Bigger and more fattening meals are being produced because they can charge more and using less healthy ingredients is typically cheaper. Much of the cost of your meal is the labor. So restaurants would rather serve you 4x the average serving size of your favorite pasta dish for $26 than a healthy portion for $18. The cost difference for the ingredients are nearly negligible compared to overhead and labor.
All of this is about profits, no one actually asked for any of this (and good luck making businesses go backwards and give up profits). I don’t know the specifics regarding the housing market and the trend towards building mcmansions, but I would bet there is a profit incentive and it’s not purely demand driven as well.