This is nice but ... the real "fun" of animation is handling all the variations of how to mix the data. It's easy to take a full set a bone animation data and apply it to matrices. The challenge, not sure challenge is the right word, maybe "the work" is in the all the tools and systems for using it. You can't just interpolate between frames, you need to be able to interpolate between multiple animations. You need some animations to apply to only parts of the skeleton (like allowing the character to run and shoot) which means you're some what back to sparser data ... though there are still ways to make it arrays.
In other words, getting a single animation to play will take a day. Getting an entire animation system ready for use in a modern 3d game can possibly take much much longer (exporters, animation editors, timelines, skeleton editors, state machine editors, etc... etc...)
https://docs.unrealengine.com/en-US/AnimatingObjects/Skeleta...
https://docs.unity3d.com/Manual/AnimationSection.html
In other words, getting a single animation to play will take a day. Getting an entire animation system ready for use in a modern 3d game can possibly take much much longer (exporters, animation editors, timelines, skeleton editors, state machine editors, etc... etc...)