In these cases, the work is usually about connecting the systems together than the data modification itself.

No, that's just made up work that's not required to solve a problem. Systems are already connected enough by virtue of being accessible by the same person on the same computer at the same time. Turning this into software project and building Proper Integration is only creating a tight coupling between the systems, which will only keep creating bugs and requires ongoing maintenance.

My sibling from another mother. That's exactly what we did.