

Unless you are using a tiling window manager it is not same thing. You have to spend time dragging and resizing the two windows with your mouse in order to put them the way you want. And while it may not sound like a lot if you are doing it pretty often it adds up.
If on the other hand you can open a link in split view with the current tab just as effortlessly as middle clicking to open on a new tab, I can see myself doing it all the time. This is one of the reasons I was testing out the Zen browser recently, which is a Firefox fork that has the feature.



This is hilarious.