Why are small pieces of space debris considered to be more dangerous?

Space debris is junk, garbage, trash orbiting the earth. Space debris includes broken old satellites in the space, piece of launched rocket. Some pieces of space debris are very small even tiny while some are large. The larger ones can easily be tracked by a satellite operator so that a moving satellite can be maneuvered into a safer place. As easy as this might sound, maneuvering a satellite to a perceived safer place can turn out to be a dangerous zone for the satellite because the place is filled with tiny space debris which were not seen by the satellite operator.

The reason is that, there are millions of tiny pieces of space debris in the space, unlike the larger ones which can be seen, those tiny pieces of space debris cannot be detected because they are too small with their size less than 1cm. As tiny as a space debris can be, it has the capacity to destroy a moving spacecraft if undetected, that's why spacecraft uses radar to dodge space debris