WikiTree policy (as I understand it, at least) is to limit the content on Category pages. The content on those pages should describe the purpose and scope of the category, which typically needs to include some information about the topic. Informational pages about the topic should be created as free-space profiles.
That Canton of Basel category page does not have a lot of content, and most of it is reasonable to include on a category page. Ideally, however, there would be a separate free-space profile about the Canton of Basel, to include content on the History of Basel and other topics. A link to the free-space page should appear prominently in the descriptive section of the category page. It peeves me when a category page for a place features prominent links to Wikipedia and other non-WikiTree websites, but is silent regarding the existence of a WikiTree free-space page where one of our volunteers has assembled and presented information specifically relevant to the genealogical aspects of the place.