Self hosting is sometimes easier to do than to argue with data governance about putting the information out a system that is offprem. The additional precautions for HIPAA or PII data that may show up in the comments or attachments can problematic. There are far too many users of all stripes that copy and paste data that they have access to without doing a check on it to see if it really does belong there (and if it does belong in the issue, then applying appropriate permissions to the object).
Usually, if it isn't better from a staff-perspective or better for the customer, self-hosting or self-building is less likely to be the answer these days.