Jira has a native link handling functionality that displays links in-line on issues. To recreate the same behavior, I have to create a custom field for the link to target (meaning I end up with a bunch of extra fields) and need to reciprocate across all of the systems being updated (so, an extra field in Jira/GitHub/etc.).
If I could have it handled by the external link utilities instead, I could have consistent behavior across all of these link types and not need to add to system bloat.