Depth of Field controlled by F-stop is only one aspect of visually isolating a subject when composing a scene. Perspective is another important aspect.
Perspective is determined by the len's focal length*; a long focal length lens makes background items large and paradoxically often less distracting than if they are small. Here's a good example:
With a long lens it is also easy to adjust your position to effectively remove items from the background. In the top photos above (long lens) it would have been easy for the photographer to shift his/her position a little to the right & remove the car from the scene, and not so easy with the shorter lens.
Dave
* there is a one-to-one relationship between focal length and distance to the subject for the same subject size in the viewfinder.