Why escapism is the dominant theme in Glass Menagerie?

Escape

Tom wishes to escape from his life, just as the magician escaped from the coffin. He is most impressed by the magician's ability to escape without destroying the box or removing a single nail, and he marvels that anyone can accomplish such a feat. Tom's goal is to likewise extricate himself from his life without damage to the coffin that is his family – Amanda and Laura make him feel buried alive – but in the end this turns out to be impossible. Tom escapes, but he remains haunted by the memory, a bent nail forever poking at his conscience. Laura and Amanda, on the other hand, have no possibility of escape - they are both trapped in that coffin by financial insecurity and lack of social opportunity, but Amanda feels it most acutely because it is she who has known and can imagine the outside world. Ultimately, Tom realizes that escape cannot come without an internal price - that there is no such thing as freedom without a terrible cost.