Amazon is better than Walmart because you can search for and buy what you want when you want and have it show up the next day, and the prices are generally good enough.
Reviews are a nice touch, but those just need to be “good enough” to differentiate cheap chinese crap.
It’s not rocket science.
I often come to Amazon and search for something like "washers" and skim through the "recommended" items until I find a pack that's a good value. But from an attribution standpoint, that sale is more the result of "browsing the aisle" than a recommendation. It's not like they recommended hairspray, which i bought in addition to the thing I came there to buy.
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.
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.