Try reading the concept a little deeper.
✅ Modified 1-3-2 that can be 1-1-2-2
By blocking DoubleBarrier, and DoubleOffTank.
It means you can buff barrier tanks a lot, all up to the same power level. With no concern if 2Barrier/0Barrier is too overpowered/underpowered.
To the point where maybe we end up with a 700hp Reinhardt with 90 damage hammer swings, and all the other barrier tanks buffed to similar levels.