Sure, you can argue that library use is copy-pasting, if those snippets you're pasting come with regression tests and have been code-reviewed by multiple people.
I'm going to go ahead and suggest that a tremendous number of encryption mistakes are made specifically because people copy-paste library invocations without understanding what they're invoking and why. When you just sling a chunk of code into a project without understanding what you're doing and why, the potential for bugs goes through the roof.
