I use Kagi Search for everything now, except for image search. For that I find I go back to Google, because Google's image search lets me click on an image result and see other similar images to the one I clicked on. That gives me a better chance of narrowing down what I'm looking for. I can click an image that's kind of like what I'm looking for, and see others with similar features, click one of those that's even closer, etc, iterating towards what I want. (Sometimes the chaining goes off in unexpected directions, but that's sometimes useful too.)
Kagi's image search is good, but it's a single result list, a single approximation layer, with no way that I've seen to do a "more like this" sort of function to get closer to what I want.
What I'm looking for is, basically, what Google does for this. If you feel there's a reason why you shouldn't... fair enough, that's your call. If I have to keep popping out to Google for my image searches, I can do that. I'd just prefer to use you guys for everything (search, translate, maps, etc), and never touch Google again. :-)
The feature ideally would work similarly to Google: you do an image search, get rows of matching images, click one, and it takes you to a page of images similar to the one you clicked.
Google's works slightly differently on the desktop and on iOS mobile. On the desktop, it takes you to a page with original search results on the left, and the image you clicked on, plus similar images to it, on the right. Thereafter, each "similar" image you click on the left or right sides replaces the one at the top of that "similar" column, while the original search results remain on the left. On mobile, you click on an image and it goes directly to a page with that image at the top and similar images below it, and each new click rewrites the page with that image at the top and similar images below it; you then use a backup arrow button to go backwards up the chain towards the original search results.