Well... if we had a constant stream of inventions so that people will always have things they'd love to have but struggle to afford, then there won't be a need to induce demand. But we don't have nearly enough: people have more spare cash than inventions they want, are produced every year.

If we don't induce demand by brainwashing, what will people do? They will keep inflating bubbles buying up stocks (making economy even more unstable, and eventually undermining themselves), houses (making sure new generations can't buy theirs, depressing birth rates and giving rise to political radicalism), and crypto (which is absolute insanity). People need to be given ways to spend their spare cash, and nudged to do it as opposed to "investing" that cash (which is, in the true meanin of this word, mostly impossible because there aren't enough inventions to invest into).