They key advantage to video (and the reason why YouTube seems to keep expanding to encompass more and more subcultures) is that video formatting is also inclusive to text, audio, and still image formatting. You can only upload text to a blog, and you can only upload audio to SoundCloud, but you can upload everything to YouTube.
Blogs are perfectly capable of embedding media as appropriate, including videos.
On the contrary to your suggestion, blogs (or more specifically, webpages) are what can do more than anything else, since they can also feature interactive media. See <https://ncase.me/trust/> for an example.
Whether or not this is expected, standard, or the author thinks it's worth the effort is another thing.
Are we talking slide shows on a youtube video here? Because to me those are probably the worst of all worlds. Low information density and not searchable.
