It is precisely because the video exists that you have the opportunity to correct the misconception, which is exactly what happened with the discussion in your example. Had it been a photograph, that context would have been lost and no one could refute it.

The compression artefacts help there, because they make it very clear this was taken from a video, meaning one should look up the source because it probably exists.

That is a perfect example of how a photograph could be worse than a video.