It is, people just don't know about it (it seems?). In Firefox, just press '/'. You can also toggle 'Search for text when I start typing' in about:preferences#advanced.
Totally not even remotely the same thing. You need to type several times as many characters in the best case and it will select the first instance of a string even if it's nowhere near your cursor.
Additionaly you can't search for links that are graphics
Actually, it doesn't select the first instance in the document but rather the first after your cursor. And you can use ' instead of / to select only links.
It allows you to open links without using the mouse, so saying it is not exactly the same thing would be more accurate than saying it is "not even remotely the same thing."
