satellites find things millions of miles away but why not Mh370 why the search for the flight is decreasing in level daily ?

Satellites today can track asteroids thousands if not millions of miles away from us without any technology coming from the other source its tracked,they also managing to discover new things along the way. My question is how-come they cannot find the missing flight mh370 with all the modern technology that the aircraft was built with yes they only have so many days before battery life is lost and then lose contact with signal transponders, So sure if they can find objects around us at greater distances without technology then why not continue the search at an intense level for the missing plane??

Maybe it will be one-day used sometime in the future for horror events that will be another made up story created by our world leaders? hopefully someone can answer my question thanks?