It’s not about mythology or Mesopotamia. Those numbers are called highly composite numbers (HCN) and superior highly composite numbers (SHCN) and are great for doing calculations (especially divisions) in your head because they have a lot of factors. That’s why they were used everywhere before calculators were a thing.
That’s probably why Mesopotamians chose them: the convention traces back to them. Measuring angles in degrees also traces back to them.
Still, those numbers/units are quite arbitrary & introduce unnecessary conversions. Radians are dimensionless & require no conversion. Converting seconds to a more natural unit like days involves reintroducing those highly composite numbers that fit better in base-60 than the base-10 system we now use.