We use todos for tracking actions that come up at governance meetings. As things change these actions may no longer be relevant, but we do not want to delete them completely. Marking them as complete may make it appear that actions were taken that have not in fact been done.
Using todos is more challenging, people reviewing past meetings may have a mistaken impression about what has been done.
Allow some kind of archive or no longer needed status for todos that were not completed but are no longer needed.