Safari lets you drag and zoom so it’s still more than just a zoom function.

Also, Boxed already replied by complaining about rotation in the Map app imagine the hate if Safari did let you rotate. Removing features is just as critical for UI design as adding them.

I agree that Safari would be much worse if it allowed rotation, I think most of the places where Apple currently allow rotation (such as in the photos or files apps) would be better if rotation wasn't allowed, but we're not discussing my taste or yours in UIs here.