I think you're wrong for one simple reason: business logic.

Business logic is complicated and rarely defined by a developer but by a product manager. Often you can understand what's being done in the code, but the WHY is necessary to understand why it's there and what it is trying to do. I believe giving a brief synopsis of the business logic in a method comment and, if it's not super straightforward, a brief overview of the steps or algorithm, is incredibly useful.

I guarantee you won't be able to figure out what your program is doing by looking through years old wikis left by product managers no longer at your company.