I think the idea is true if you reverse it: there are a lot of cheap air fryers that are not worth buying over a one or more "good value" alternatives.
This also lines up a lot better with other complaints with amazon: their inability to get rid of counterfeit sellers, the degree to which their reviews (and listings) are gamed, etc. Arguably the reason people buy garbage on Amazon has more to do with their lack of interest in policing misbehavior than ads (though perhaps the ads are the financial incentive to keep being lazy).
You can see this with the knockoff[1] plugin that flags "no-name" brands on amazon. Sometimes this takes out the listings you want and you need to consider it, but I think it's a pretty effective counter to the kinds of scammy ads this poster is frustrated with.
> there are a lot of cheap air fryers that are not worth buying over a one or more "good value" alternatives
OK, but the customer is the only person who gets to decide what that means. "Reversing the idea" is just making the same (imo faulty) assumption that the author is, which is that there is some known "good value" product that everyone should be buying. What you perceive to be "good value" might be "overpaying for useless features" to someone else.
If anything, allowing for ads like Amazon does is probably more likely to match a customer to the product that's "good value" for them. If someone consistently buys products after sorting price low>high, then you know something about their purchasing habits - giving them a recommendation to buy a $450 air fryer because it's "good value" (decided by who?) isn't helpful when they really just want something barebones for $100.