> 80% is spent on motor skills.

The cerebellum isn't just for motor skills. It's more of a place where very commonly used patterns get a bunch of dedicated wetware so the computation is superfast and precise. In an (undoubtedly very limited) analogy a bunch of FPGAs to complement the general processing. It does make a lot of sense to use this functionality for motor skills, though.

See:

- https://pmc.ncbi.nlm.nih.gov/articles/PMC4089997/

- https://pubmed.ncbi.nlm.nih.gov/38663092/