Think of a live performance stage as having four invisible walls that box in the action area. When performer then “breaks the fourth wall” that means there is a direct interaction with the audience by shattering the pretend “wall” that invisibly stands between the live space and the perceivers.
I am against breaking the fourth wall in every example ever written, created or staged.
Breaking the fourth wall is an emotional swindle and an intellectual mendacity consciously applied to force audience interest through clingery instead of tension building.
When a performer breaks the fourth wall to basically narrate a story to an audience — the audience isn’t being drawn into the plot — the audience is being falsely made part of the spectacle and, in the Aristotelian process, that live performance can never have a satisfying or cathartic end.
When live performers address a live audience, the sacred and magical necessity of observation and imitation are destroyed, and the drama is doomed to fail.
Instead of drawing the audience into the live drama on stage with persuasive conflict and irrevocable change — the audience is directly addressed — and the process of exploration and unification of purpose is no longer possible as the audience becomes part of the live stage.
If you want an immediate, but false, connection with an audience, then breaking the fourth wall is an effective cheat and a crutch.
If, however, you want to craft the best possible performance, you will leave the fourth wall intact — the audience always prefers to watch the action from behind the safety of
that agreed barrier — and audiences are more willing to open their public joys and their private demons for introspection if that necessary wall of privacy is left intact without a false shattering.