Because in a condo, the building itself has a say. The association exists to protect the residents and the asset, and screening incoming tenants is part of how Florida associations do it. A renter in a condo building is applying twice: once to the landlord, once to the association.
The association step typically involves its own application, fee, background screening, and sometimes an interview or orientation, with processing times that vary widely between buildings. Some buildings approve in days; others take weeks, and that difference should shape which buildings you target when your move date is fixed.
This is a place where an agent's building knowledge pays directly. Rangely knows which buildings in her coverage area move quickly, what each association requires, and how to package an application so it clears on the first pass rather than bouncing for missing items.