Problem

when you try to symbolic something using ln -s xx xx, you may get Operation not permitted error. Even sudo can’t solve the problem.

Solution

You need to enable full disk access to your terminal.
Go Setting -> Security & Privacy -> Full Disk Access and add your terminal app in the list. (I’m using iTerm, I guess adding in Terminal works too)

Quiz all instance of your terminal app and open again, you should be able to link now.