The problem has gone far beyond spam of the "doctors hate this one little trick" variety. Have you looked at Google Shopping results (which are now prominently

The problem has gone far beyond spam of the "doctors hate this one little trick" variety. Have you looked at Google Shopping results (which are now prominently displayed at the upper right of the search results page if it detected you were looking for a product), recently? A significant number of the results are outright fraud from fake websites. During the pandemic when it was impossible to find a bicycle anywhere, you could search for a popular model name and be presented with dozens of purportedly in stock bikes at or below MSRP. Every single one of the listings would take you to a web retailer, based in Asia, that was completely fraudulent. Most of the sites would have been created within the last couple of day (to avoid negative reviews when you searched the shop name) so there was no way that something like PageRank was organically producing those results (and these were not explicitly labeled ads, these were showing up in the Shopping results section where the Knowledge Graph usually went).