Also if you don't care about permanent residency, Japan will give pretty much anyone with a degree and a job offer a working visa. And working visas aren't tied

Also if you don't care about permanent residency, Japan will give pretty much anyone with a degree and a job offer a working visa. And working visas aren't tied to an employer, you're free to change jobs, so unless you want to work freelance without a sponsoring employer, PR isn't super important. The lack of skilled immigration to Japan has nothing to do with strict immigration law. The fact of the matter is simply that Japan is not an attractive job market for skilled professionals. Salary is low, the language barrier is high, and the work environment is notoriously poor.