Paper forms can be filled in by different people with different roles at different times. Customers can fill in their personal data and possibly leave blank something they don't understand. A clerk can review the form, ask the right question and fill in the missing field plus the remaining ones.

"Fill in what you know and leave the rest to us" is a simple and cheap to implement GUI compared to a full fledged workflow. It could bootstrap a process quickly at the cost of some extra labor in the customer facing department. Maybe they have that extra bandwidth and the sw developers don't.