There are reasons to use both for bench work and reasons not to use barbells. In all situations with using an external load (especially barbells, dumbbellls, kettlebells, etc.), the use of caution, control, and proper progression is essential. I do not use bench press or shoulder press with clients in the traditional form. While many of my athletic clients perform these lifts as they are given importance in recruiting, I teach other integrative movements for the intended movements and muscle groups.
I do use dumbbells and barbells, but I doubt that many reading this use them in the same fashion that I do.
Either one can be used BUT dumbbells have a slight advantage over barbells.
Dumbbells place a load on each side (this will indicate if one side is weaker than the other). Barbells won’t allow you to easily see imbalances because weight can be lifted without consideration of which (if any) side is weaker.
Dumbbells create more isolated efforts for each individual arm and require more stabilization when moving through a range of motion. With the exercises mentioned, dumbbells or other single-hand weights may provide a greater range of motion but will likely limit absolute amount of weight lifted. Using a barbell lets one balance out the weight load usually resulting in an increased absolute weight lifted. Both are great and require stability from the shoulder girdle and the abdomen because each are free-weight exercises.