Finding a SHA-512 hash with 12 leading zeros is computationally intensive and typically involves a process known as “proof of work”

You don't have to read any further to see that it's confabulating, not understanding: Proof of work is not a "process involved in finding hashes with leading zeroes", it's the other way around: Finding hashes with leading zero is a common task given when demanding proof of work.

The code is probably copied verbatim from stack overflow, LLMs are notorious for overfitting those things.