My thoughts exactly. It's nice to see and probably very satisfying for the creator. I can also imagine using this in some circumstances especially during presentations or teaching.

For my daily work, one obvious problem is that I can't see exactly what changed between revision n and n+1. That's what really makes diffs + commit messages useful. With the slick animation, I know where it changed but the information on what exactly was modified is lost and with it, most of the reasons why I use git diff at all.