I can't comment on the economics of it but amazon search is awful, and I think it's by design, not just by design though. I was recently searching for some draw runners of a certain fixed size. Just cheap ones for some drawers I'm making for a workbench. Found some cheap ones but not the correct length, but it made me realise something; If I sorted by price low to high the cheap ones did not show on any of the result…
I built ShopSmart-AI. It's not a "better search tool" but it is a Chrome extension that adds some sudo-filtering to Amazon results. Like the ability to filter out sponsored products, spammy seller names, and products with low review counts. It also has some other AI features you may find handy if you want to check it out.