Based on own experience, there are a lot of systems out there that will only injest certain kinds of data via an FTP drop off. They won’t change or update their systems, but everyone who wants better visibility to the data they’re dropping into the ftp system will have to write something to cover that.
So, you’d probably need to build both halves of the FTP chain, but each would still need to deliver the value add if only half of the new system was being used.