Once a war begins, it is never something you can stop just because you want to.
Bringing the war into the ordinary world was initiated by the wizarding world, but when they wanted to stop, the ordinary world did not stop as they had expected.
True, magic was indeed extremely powerful and difficult to guard against when used for solo breakthrough, assassination, infiltration, and sabotage. Yet once these methods were thoroughly studied, devising countermeasures was not all that difficult.
Chapter 465