On Mac I have everything maximised, so I have to drag the thumbnail on top of another thumbnail, which then splits them unevenly, so I have to fix that, then to undo it you have to understand maximize one half (and to get back to where you started at least) re maximize and drag it back I to it's position. Plus there are the steps to take an existing tab and make it its own window in the first place.
Compared to like right clicking a tab and "show on the side" or however it will work..