Here is the set up of a potential bracket defense. 3 (red) is the under cover of the bracket, 7 (red - can be) the deep part of the bracket
Cutter (blue) cuts to open side, her defender comes with and so does the under of the bracket (3)
The handler can dump, 3 (red) stays as under bracket
If there is another in cut, that draws away defenders. multiple deep options... that's usually why they are only good for a few plays
now let's reset...
open side bracket, same as before
to break the bracket, offense can flood the open space, but one offender can now use the whole field for open space...
Now 3 has the entire field to work with, and their bracket isn't effective