well friend u r right
the world may not depend on led i accept it
but i can quote one example
its the use led in each domain like, vehicles,houses,hotels etc
once i was going through an article it said the leds are available in the wide range from micro amperes to few amperes!! also they cost accordingly(may be from few rupees to few thousands!(Indian currency))
and there r leds which have the wide range, some output light in different colors but some different in heat or even UV?!