what's the value in having an afterlife that is basically forgetfulness and longing, as it was for the Greeks, even for those who are good?

The ancient Greek have definite belief that there is life after death, but such life is meaningless.

Explanation:

In constant remembring by the living, the dead of Ancient Greece continued their existence in the after-life.

The after-life, for the ancient Greeks, consisted of a grey

and dreary world in the time of Homer (8th century BCE). By the time of Plato in the 4th century BCE individuals were rewarded for their pains once they have left Earth.

The Greek gods only rewarded heroes who were still living heroes that died were ignored in the afterlife with reasons best known to them. However, it was considered very important to the

Greeks to honor the dead and was seen as a type of piety.