Smith is the biggest waste of space in the gym. The question should be integrated vs isolated moves not DB vs BB. Integrated moves force you to overcome resistance the way nature intended - starting with the core and radiating outward - so they are superior in building athleticism (strength, power, explosiveness). Some DB moves are good though like DB split cleans. If you want to look good but don’t care about your body’s actual ability to do anything, do isolated exercises.
Sometimes, just to pi$$ off someone, i use the rack to do my traps.
Both