I've been using Kagi for a while. I'm totally on board with springing $10/mo for good search.

The biggest thing that worries me about Kagi is that, in order to be using it and paying for it, I have to log in, across all my devices. I'm literally collaborating on the process of someone doing much, much finer-grained and definitive tracking than other search engines currently do.

While Kagi assure me they aren't putting all this information together... I am giving it to them, and that gives me pause.