[wongarsu]

Maybe there is also value in 2d datasets that aren't hand drawn. A lot of TV shows are made in Toon Boom or Adobe Animate (formerly Macromedia Flash). Those also do automatic inbetweening, but with a process that's closer to CSS animations: everything you want to move independently if it's own vector that can be moved, rotated and squished, and the software just interpolates the frames in between with your desired easing algorithm. That's a lot of data that's available on those original project files that's nontrivial to infer from the final product

[yosefk]

I doubt you can learn much out of tweened flat cutouts beyond fitting polynomials to data points. The difficulty with full animation is rotation & deformation you can't do at all with cutouts. (Puppet warp/DUIK cutouts are much less rigid than Flash but the above still applies)