Why is Class S always ranked higher than Class A in anime?
originally, "S" designated a special class, eg. things that simply didn't fit into the normal ranking system because they were too unique or were valuable in ways the system couldn't quantify, which is an obvious fantasy for a highly standardized and hierarchy-based society.
That concept just devolved until the point where S ranking just means "A but better."
So basically something like:
A, B, C - battleship, cruiser, destroyer
S - carrier, submarine
Where S is simply not the same kind of thing but may have advantages over the primary hierarchy depending on situation.
it's not just in anime, i don't remember where did i read that, but it's because "sugoi" starts with S or some shit like that, so for me it is for stuff out of the ordinary scale, pic related for example is a baseball stadium