The issue is that in the sim, they’re emulating cameras vs just a view. And that’s how zoom on a camera works. It zooms into everything in its field of view, not just the subject. You want the effect of phycially moving the camera closer to your subject (plane) without zooming in the background. You just can’t do that in the external view.
As suggested, the drone view is your better option if that’s the effect you want. Just as a tip, if you happen to have an XBox or other dual analog controller laying around unused, you can use that to control the drone, and it makes it super easy to use and move vs using the very awkward keyboard commands.