These are a few of the advantages of using DBCA:
You can use its wizards to guide you through a selection of options providing an easy means of creating and tailoring your database. It allows you to provide varying levels of detail. You can provide a minimum of input and allow Oracle to make decisions for you, eliminating the need to spend time deciding how best to set parameters or structure the database. Optionally, it allows you to be very specific about parameter settings and file allocations.
It builds efficient and effective databases that take advantage of Oracle's new features.
It uses Optimal Flexible Architecture (OFA), whereby database files and administrative files, including initialization files, follow standard naming and placement practices