I agree. Doing this would be stupid as hell, since it just opens you up to a lawsuit over stealing company secrets. Having knowledge in your head is one thing. Having actual code is another entirely.
I'm not sure I'd even take most corporate code if it was offered to me. It'd potentially drag me into any future breaches or noncompete violations, and have no upside I can think of. I'm honestly struggling to imagine why devs would bother taking most code when they leave a job.