In fact you should be rotating exercises from time to time to hit slightly different muscles.
Fair warning, you will not be able to press as much with dumbbells as you do with a barbell, as more stabilizers come into play.
-Having a big tool box is great but it means nothing if you lack a set of standard screwdrivers and a hammer.
-The Pareto principle: 80% of the effects are from 20% of causes. All the other small details will only affect a small portion of results, 80% of causes will contribute to 20% of the effects.
It depends on your primary goal. For a strength program, I would never switch out the barbell bench press for dumbbell bench press. I might recommend adding DB bench press and/or dips as accessory movements if the chest is a weak point or if it isn't developing with good symmetry. If you have one very dominant side of your chest, DB bench press is a good way to force both sides to work equally hard and hopefully balance them out for example.
In a hypertrophy-focused workout where the lifter is mostly concerned with muscle mass gains, the DB bench press can replace the barbell bench press of course because strength gains aren't the primary focus. You will still get stronger over time and within the parameters of the lift if you're training properly, but you will be able to move more weight with the barbell bench press (thus making it superior as a primary chest exercise in strength training).
DB bench press and dips might also come into play as a more advanced lifter, if you decide to do a routine with lift progression.