Cookie banner is imposed by the underlying hosting, Miraheze, which is hosted in UK where they’re mandatory.

I don’t currently have the ability to host a publicly facing wiki myself, so the next best thing is Miraheze. They’re a non-profit hoster who do not impose any ads or tracking, so they meet most of the requirements of hosting a privacy conscious wiki. They do have their issues, such as the cookie banner as well as banning contributions from TOR, but despite that, I do not know of a better option short of self-hosting.