can you imagine if every site that linked to yours had a bar at the top of your page that said "back to facebook" or "back to wikipedia"? mobile web users know how to use the back button but google is taking up your screen real-estate to drive traffic back to google.
this reminds me of sites in the early web that used to link out to sites and frame them with a banner at the top. websites countered this with frame-breaker scripts -- but publishers really shouldn't have to do that.
Hugely agree - this feels like a dark pattern callback to one of the early web's uglier constructs.
I mean - running a "we'll host your page for you in exchange for injecting a toolbar" service isn't necessarily an evil thing to do. But there's no reason to opt people into it just because they're tying to perform well on mobile.
I suspect the toolbar is there to clearly identify the origin URL. As you can see, safari gives you no hint that this page is not actually google: https://imgur.com/a/2BtMX
As for the X button, I suppose google wishes people to use google search result like a news reader. I agree that it is redundant with the back button but the interaction does seem faster (I suspect that the page is actually loaded in an iframe on top of the results page)
But I doubt that Google's AMP cache will respect existing headers (the very nature of the cache stuff means that they won't, but what they will do to non-cache headers on an item is undefined AFAIK and so they will probably just strip them).
a quick look at an amp page (from google's cache) shows it's being served with x-frame-options:SAMEORIGIN, so looks like the linkis thing won't work with them.
this reminds me of sites in the early web that used to link out to sites and frame them with a banner at the top. websites countered this with frame-breaker scripts -- but publishers really shouldn't have to do that.