@mattches You have to resize or move the current window and you also have to open the destination window.
The method I suggested lets you move items without having to do either: no need to open other windows or resize (or move) the current window.
For a single operation the difference may not be that significant. But would you want to keep repeating opening and closing other windows if you had a series of tabs you wanted moved to different windows?
In my case relocating tabs to other windows is something I do often, in part because various extensions or features inherent to apps end up opening tabs in a different window than where I want them.
The method I recommended also lets you open a lot of unrelated tabs in the current window and then, without breaking much of your workflow, send them to the windows where you actually want them to be – again, without having to open any of them.
These seem like worthwhile advantages to me.