> laws of nature "must" be shorter

Coming at this from philosophy of science rather than as a physicist, I feel those quotes around "must".

I think you also recognise how that might be a sort of "fundamentally wrong assumption".

Imagine your words replayed 50 years in the future, not on physics but applied tp the problem of general AI/sentience.

  "The equations that we already have are sufficient to describe human
  thought to 99.9999999% but they are a hodge podge of several
  different theories...."

Whereupon a psychologist/neuroscientist in any epoch would say:

  "Why on Earth are you looking for a *singular*, unified explanation
  of human experience?"

What you can have is a set of "best they can be", internally self-consistent and well evidenced theories, none of which can ever fully explain the system - and that is the nature/feature of the system. Isn't that what Godel and Russell showed us?