Is this true? I thought the primary way Wikipedia dealt with vandalism is by treating it as just another edit, the bad ones of which are more likely to be nixed by subsequent edits.
My personal experience is that a tiny percentage of vandalism requires more power to solve. Is that not the case?
That is exactly the case, however a tiny percentage of a very large number is still quite a large number. Most vandalism doesn't require admin intervention, there is still quite a lot (often the worst kinds) that do need blocking or protection to stop them.