JIRA supports 'archiving' versions but does not support that for components. That's bad because list of components may grow to a very large extent; full list of those components may be still useful for searching, but not all the list must be necessarily available for selection in a dropdown field when creating an issue. This creates a big usability problem for QA folks.
Example: every release adds, say, up to 10 components; relevant testing that follows mostly focuses on those new components rather than existing 100, which forces QA personnel to scroll a 100-entry list every time they file a bug. Scrolling a 10-entry list would be a whole lot easier and error-proof.