Right now, Kagi is, overall, slightly better than other search engines.
Most often, search results will be no better - Or no different at all. Other times, they'll be noticably improved. But, for how little improvement Kagi shows over its competition, I'm skeptical of any reason to stay with Kagi other than having money to burn.
It's nice to have a slightly improved shot at a query that other engines can't find; And also to have a small reduction in the amount of irrelevant/rubbish/generated articles overall.
But it's just not enough to buy Kagi.
I don't have a feature in mind, but you don't have anywhere for general feedback - I guess because you don't want feedback?
Not a good look, to be honest.
Barely better searches. Just.... Barely better.