What is happening with safari swipe to go back functionality, every time I swipe back it shows me a cached version of a page and then reloads it making it unusa

What is happening with safari swipe to go back functionality, every time I swipe back it shows me a cached version of a page and then reloads it making it unusable and irrational, what is the point of showing a cached version for split of a second if you are going to reload it again ( happens on both iOS and OS X , Adblock is not installed)