Neither style is automatically better. The right choice depends on the subject, the body placement, how visible you want the tattoo to be and the kind of visual language you keep returning to.
What realism requires
Realism uses gradients, texture, proportion and controlled contrast to create depth. It often needs enough size for the details to remain legible, especially when the subject includes a face, animal or complex object. References with clear light and shadow give the artist a better starting point.
What makes blackwork different
Blackwork can be graphic, ornamental, illustrative or abstract, but it relies on the strength of the silhouette and the balance between ink and skin. Bold shapes can read from a distance and often make a strong choice for larger compositions or cover-ups.
How to choose
Ask yourself whether you are drawn to an image because of its texture or because of its shape. Then check artists who repeatedly produce that result. The scale and placement can shift the answer: an idea that feels like realism at one size may work better as a graphic blackwork piece at another.
Bring both the subject and the mood you want. A consultation will show what the skin and placement can realistically support.