Being confident that the ancestors in your tree are correct is not the same as having confirmed those relationships with DNA. The 'potential' matches you see on WikiTree are only that, potential. WikiTree does not do any matching. You have to do that on your own, at either your testing company, or at GEDmatch.com. If your only DNA matches are with your siblings, the 'confirmed with DNA' entries for more distant ancestors should be changed to 'confident'. I'll send you a private message, and we can discuss this further.
Using DNA on WikiTree can be a bit intimidating, but that doesn't mean that you can't use all the other features of WikiTree membership!