It's a fair question. Keeping in mind that we literally had nobody who'd ever used Oracle in their careers (or at least beyond fairly basic uses a decade ago)...we had a fairly simple set of tables, one of which had a CLOB attribute.
Every single export option available in Oracle SQL Developer truncated the CLOB field whenever it felt like, and half of the exported formats were exported without escaping content in the CLOB so that they were unparseable on import.
When we finally called in the Oracle consultants, they said "we never use the import/export tools in SQL Developer" and moved on to SQLLDR, but failed for exiting reasons last seen in 1980's computing like "Error in Index ORA-42321" and then other issues with the parser.
Data Pump didn't work for some reason only the consultants know, but "minor version mismatch" was something they liked to say.
I don't remember the final solution, but I believe it was a hackneyed combination of writing some python code to connect to one of the databases, dumping the table data to a bunch of INSERT statements then just copy-pasting the whole output back into SQL Developer and running it in chunks until everything could be inserted into the new table. We couldn't just write more python code to pump the data back in because of some permissions problem that nobody could ever quite resolve satisfactorily. We also couldn't just load the file through the SQL Developer because it would only load files that were sitting in a specific, inaccessible directory on that specific server, not through the GUI.
I think this was when the lightbulb went off in all of our heads and we collectively realized "it's this terrible on purpose"
Total shit show with hundreds of thousands of dollars flushed down the toilet for no additional capability, huge program delays and a good reminder why nobody uses Oracle for new starts on software these days, it's absolute garbage and a curse on any organization that sustains it.