This might be solvable with T64677: VisualEditor: Merge the media editing and gallery editing dialogs, except that it might be more complicated than that.
The Gallery dialog feels cramped when I search for images. The Media dialog's search box is bigger than the regular dialog; the Gallery dialog is the same size, but I only get to use three-quarters of the width because the column on the left is reserved for the current list of images. This means that I can usually see (most of) four to six images at a time.