You have a chance to win a functioning back button in a loot box.

Complaining that games use dark patterns while posting on a site that uses even worse patterns. That's a paddlin'.

I can't imagine this ever being intentional. No one tries to leave a site and goes "Well the button didn't work, guess I'll keep browsing".

It's pretty much always the result of a broken redirect / history api usage. You go back to the page which redirected causing it to redirect again.