I was just getting interested in Neeva as a paid search engine with some cool AI tools where you're not an advertising target because you pay. This explains the sudden refund from Neeva - they apparently got bought out and are no longer being a search engine. I don't really know what to make of it all.
I suppose it makes my decision between it and Kagi easier - I don't really have a choice. Kagi is a lot more expensive, but I get work to pay for it. Though that does make it harder to potentially recommend to other people I know.
Not that I ever thought paid search would massively take off, but unlike many tasks, search can be centralized enough on a per user basis that something other than ads is worth exploring.
I was a paid Neeva user as well and signed up a few months before it shut down. I'm pretty dissappointed because search results felt almost as usable as Google's. Other solutions like SearX have been hit or miss from my experience, so I'm giving a selfhosted instance of LibreX a try.
While it costs more, I would suggest also trying Kagi. I especially find the forum lens useful for my work / tech related searches, where usually the actual answer, if it can be found, was on a forum site.