You do know Chrome on iOS is just safari with a skin...
"... with a skin..."
Much more than just a skin.
Apps arent anymore using the old api, uiwebview rendering, as they were forced to use couple years ago and other browsers sucked.
What comes to Opera for example, It is even using its own rendering engine in their cloud if you have enabled data saving.
So basicly any browser nowadays can be built to be as fast as safari. It is not just the ui but the whole package. Of course they are still using the api that apple provides, but they arent suffering anymore from this "only a skin"-thing. Safari has only one advantage in ios devices: it only can be the default app. But luckily links from gmail app opens straight to chrome =}
And... Some browsers have even much better
skin (gui) and functions than safari