If I search for 1440p IPS monitor, it will mix in some monitors that aren't 1440p, and some that aren't IPS.
I'm not sure if it's because they don't want to solve the problem, because they don't care, or because somehow having customers need to spend more time on Amazon to research their purchases perversely leads to people spending more time on Amazon seeing other items they might also later buy.
note, I have never implemented search but suspect it's hard problem.
Still Amazon's search is pretty awful. I've found adding something in the category I want to my cart gets me better results than being on the item itself. In other words I might search for "wrench" and it shows me 50 items of which 2 are remotely close the the type of wrench I'm looking for. I click one, get new page for that product and below it shows other wrenches but they aren't remotely like the one the page is for. So I add it to my cart and suddenly it suggests a bunch of stuff that is actually close to what I wanted.
I also don't understand the pitching me things I already bought. I get pitching me disposables I already bought. I don't get pitching me a monitor or soldering iron or another mouse or keyboard. I'd think either via statistical analysis or via manual tagging they could figure out what items are more likely to be purchased again and not recommend another PS4 just after I bought a PS4? But who knows. It could be this is harder than it sounds or it could also be they suck at search or haven't gotten around to it yet or ...
I'm not saying Amazon isn't full of dark patterns and other problems but if there is one thing I've noticed on nearly every online store since the dawn of online shopping, it's that there is always the odd product that has been incorrectly classified. This problem only becomes magnified when you allow 3rd parties to complete product pages.
For me though, the most annoying anti-pattern goes to eBay and how it will bulk out it's results with items from other countries even when you specifically state a local region.
search bar (on the top) for window-shoppers
selection boxes (on the left) for focus-shoppers
If I select 1440p under Resolution, I do not want non-1440p monitors in search results.
Every time it happens I want to quit my job and force them to hire me to fix it.
End of the day, search is hard and personal.
In reverse, someone looking for a Pixel 3 XL cases but only wrote Pixel 3 cases, would have been much more pissed than you were if it was has specific has you want.