I wonder what specifically Bezos meant? Similarly, I often search for something specific and see "sponsored" results that are what I was searching for, with the same item right below it as part of the organic search results. Or, I'll browse for items, then come back to purchase it later seeing it under "recently viewed." Do those count? If so, I purchase recommended things all the time. If not, I don't think I've ever bought something they organically offered on their main page with 20 years of purchase and browsing history.

Looking at the recommendations right now, they're not very good. Maybe I'm a hard sell? Sure, sidewalk chalk. You might run out of that and want more. Stuff to rekey your lock. I needed that when I bought my house a few years ago...I'm not sure why I would need that now. An air conditioner support bracket. I bought one last year much earlier in the summer.

Agreed. I think highly contextualized recommendations are the most helpful.

As another example, I frequently find the "often purchased together" section to be very helpful. That might be the only recommendation system that I've ever used more than once.

I would say that's an example of recommendations working. However, in my personal experience, I rarely find "general" recommendations helpful.

The entire isle was constructed on the fly just for you, including all the items you "compared", and their prices, and the thing you eventually "picked".