Not quite "animated", but still very nice: James Tanton Youtube
He starts with a kind of problem, sometimes applied, but often just non-standard, and then shows mathematician viewpoint on problem solution.
You may start discovering with his "Why I became mathematician" https:/...
This data from Wistia supports several of the comments:
This chart is not specialized to mathematics.
Likely the attention-span constraints are pretty much universal, independent of content (but not independent of interactivity).