So today the issue with traditional animations is that you get all humans have same height, same proportions, like for example in The sims games all adults have exactly same height though you have different body shapes. If you use mods to change height, or legs length then things no longer align, like siting on a chair. This means chairs, beds,tables, doors all have the same height.

Not sure if this diffusion is the answer but some smarter way to extrapolate existing animation to work with bodies and objects that are 10-20% different and look natural.