I use it, and like it. They dropped prices a while back so now you can get unlimited searches for $10 a month (they also have a $5 limited tier and a free trial).
First thing is I'd like to live in a world where search engines (and the internet in general) don't have to be ad supported. This is a different model so I want to support it.
But also Kagi has some nice features. My favourite is how I can block Pinterest, and boost the ranking of other sites like Wikipedia. Basically you can have some control over search results.
If you're familiar with SearxNG, that's basically how Kagi works. They run the searches on a bunch of search engines and then present one cohesive search results page. But SearxNG for me takes several seconds to get the results, and Kagi is almost instant.
I don't know if it's significantly better than the free options, but I like using it and it's pretty cheap really.
Not OP, but I copy my reply from the last time someone asked an opinion on kagi:
I use it, but to be honest I did not do a comprehensive comparison. I like it mostly for the fine grained website control. For work and some personal stuff I often look for code and can push websites like GitHub to appear more often. Or I can block Pinterest in my search results. I tried to do this in SearXNG, but this was too much of a hassle so in a way I pay kagi for convenience. I recently got a new job and will evaluate in the coming months if it is still worth the money, but right now I am satisfied. Nobody else I know would pay for a search engine, so I can understand the stance, but I am really fed up with all the advertising and enshitification so I thought why not give it a try. And yes, because it was recommended here.
Kagi is just excellent so I guess that's why. It's so good I completely forgot about Google when I tried it.
I used ddg a few years back too but I always had to use Google for certain queries and never felt fully satisfied with the search results. It felt like a worse search engine that I was using because I didnt want to use Google.
With Kagi it's the opposite. It's a better search engine than Google. It's Google results without the dark patterns and hostile behavior from google.