>We have apparently reached the stage
There used to be only 3 TV channels or so. You had things like Johnny Carson jokes causing a toilet paper shortage.
In Britain, Delia Smith's How to Cook caused 10% swings in egg sales, far more abundant and harder to affect than something like inventories of sardines. https://www.bbcamerica.com/blogs/british-icon-of-the-week-de...
A lot of that is more about lack of buffer in grocery supply chains rather than the scale of the induced demand.