When you’ve opened several panes, the pane sizing can become inconsistent with some panes being very short/narrow and others tall/wide.
One helpful feature would be a command+hotkey to set all panes to be equal sized. So for example, if you had three vertical panes, they would each take 33% of the available width. Or if you had a 2x2 grid, each pane is set to 25% of the available height/width.
Taking this one step further would be applying this to a selected group of panes.