It doesn't solve the problem with Instagram links, which in my experience do the following:
1) Open a new browser tab, with no history. 2) Close the original tab, so I can't easily get back to where I was.
That's not a fix the user can implement themselves. Holding down the back button is comparatively trivial.
Clicking "back", noticing that the site broke it, moving the mouse and long-pressing "back" (I normally navigate with a mouse thumb button or a trackpad gesture) is much more annoying than my browser just preventing this from happening in the first place.