META tags

Is declaring character encoding and such within the HTML of the page considered harmful?

How can you parse a page if you ignore its encoding? There might be some important Arabic or Chinese mention before the character encoding, so if you must parse the document to attempt to find the character encoding, it is still necessary to parse it again from the start once you know its encoding.  It is a colossal waste of CPU cycles, which, at the scale of the web, produces as much carbon as a country like Portugal.