Why are Act 1 and Act 2 are almost the same?

There are very few changes in the second act, which is seen by many as monotonous. The biggest change, however, is the reversal of fortune, which sets the stage for the rest of the play. In the second act, the stage directions have changed, time has obviously passed, and the appearance of leaves of the trees signals new life..... possibly a sense of hopefulness. The relationshp between Pozzo and Lucky has also transformed. The master/ slave relationship has changed to a relationship in which the characters, once separated by status, have become dependent upon one another. Thus, though the changes may be slight, and the repetition noticeable..... the play does move along.