Let's say that I make a post on a Stack Exchange site. That content is owned by me, but I gave the company a perpetual and irrevocable license under Creative Commons Attribution Share Alike 3.0. As long as that content is available under CC-BY-SA, anyone can reuse it under those terms.
Let's say I post the exact same content on a website, but license it under "all rights reserved" or CC-BY-NC-ND. Anyone doing a Google Search will likely find the material on the Stack Exchange site where it was posted, which would include the CC-BY-SA licensing information. If that license is appropriate for their uses, then they can use it.
CC-BY-SA is pretty forgiving. The only thing that it requires is attribution to me, identification of changes, and release under the same license. That last one is, perhaps, the biggest sticking point for someone to reuse my content, since it discourages commercial use.
The only case mentioned so far is if all of the CC-BY-SA sources stopped releasing the content under that license (for example, there were no mirrors of my content and Stack Exchange shut down and did not make the content available anymore). Then, if it's only available under the more restrictive license, that's what people have to work with.
With the exception of all sources of the CC-BY-SA content stopping distribution under that license, is there any advantage to a stricter license, such as "all rights reserved" or CC BY-NC-ND?