I would debate this and say it's not that complicated. But I don't have a replacement platform to import into. It doesn't SOUND like it should be difficult. I assume some field mapping will need to occur, as it's doubtful any two platforms will have the same fields entirely. Otherwise - is it really that bad?
It depends on the complexity/hierarchy of the data. If you have multiple tables or levels of nestled data, and the data model is different, it could be very complex.
(I work in a related field, so I’m a bit familiar).
Also, if the replacement platform doesn’t allow for importing the export file and doesn’t allow for write access to their database, then you’ll be limited by whatever imports they do allow for and the rest of the data might not be importable. Manual data entry is likely cost prohibitive and prone to errors.