Some websites optimize exit intent by breaking the back button. Some malls optimize for it by making themselves difficult to navigate. It may not be a dark pattern to you, because you know how it works, but it might influence another person. I hope there will always be engineers and designers who refuse to implement them.
why does google allow them to abuse 'breaking the back button' by hijacking your history and overwriting it with the their website?
This should not be possible, it's a horrible jarring experience every time it happens to me when I click a questionable link and try to go back to the previous page.