I am strongly in favor of migrating content into a unique wiki.
As for the editing experience, I prefer the Cause Prioritization Wiki for several reasons, partly because it looks closer to Wikipedia and because it is possible to view the edit history in a convenient way. In short, I feel more in control there and I believe it is easier to spot and revert vandalism.
In the case of an EA wiki, I would argue that the barriers to contribution are not the creation of an account or the use of the wiki syntax. Instead, they are the trouble becoming aware that the wiki exists, and the lack of trust in the stability and notoriousness of the wiki.
Therefore, and as pointed out in other comments, I would be glad if:
I'm convinced that with this early work we can have a functional, regularly edited and notorious wiki, and that would be amazing!