They tried various pricing plans although I forget if they experimented with both usage based and capped plans. Anything other than unlimited did not go over well with users. I had no desire to manage a monthly cap since my own daily usage varied so much. People had also become very conditioned to having unlimited search.

On the one hand yes but on the other hand this would also kind of set wrong incentives: to use Kagi search less because you’d need to pay more.
That’s not an incentive they or you would want.

I think what I’d like is how my mobile carrier handles their data limits: It’s not an entirely fair comparison because in that case, contrary to Kagi, there is no real cost associated with my degree of usage of the service, making them entirely arbitrary and unnecessary but besides that the unused data rolls over to the next month and that’s something Kagi could mirror.

I hover around 600-1000 searches per month but sometimes exceed 1000. If I could pay for 1000/month and accumulate a little buffer in the months where I search less, that would work for me. Though perhaps I’d still want to just simply pay for unlimited usage for peace of mind.