Off topic, but does anyone know where one gets started on making motion graphics like in that video? This combination of cool maths and animated visuals is so interesting to me, but I wouldn't even know where to begin. What kind of software is used to generate this kind of visualisation? Are there free or affordable online courses? Is there a job market for someone with this ability and also with software development chops?

I believe the maker of 3blue1brown has a open source kit for just that: https://github.com/3b1b/manim