Can someone explain me why reference images have black borders?

I would like to know what genius come with an idea to have border around any reference image. I know i can import Image as a poly plane, but i really like the options of reference images. i can set in which view will be visible or if is visible over geo or in the back. Earlier versions of Blender didn’t have this nonsense issue…

Is there way to remove the outline?

It’s just a outline color for an object… does not make sense to make it invisible… then users ould complain about the unvisibility of the borders of their objects…
May be make it a bit more pleasant fro you by changing the outline color of an empty in Blender Preferences → Themes → 3d Viewport → Empty ?

thank for the reply, but that is not real solution - it still will stay as a solid border.

You can turn outlines off in your Viewport Overlays, and if that doesn’t work, turn off Extras in your Viewport Overlays