Maybe reading the article you are reacting to would have helped:
- It is a retrospective and the first edition held place in 2011. At that time noise canceling in harsh conditions was not a solved issue.
- They actually tried the noise canceling, no box approach at the 2022 event. They reverted to boxes for 2023 because it still need tweaking to drop the box altogether.
Have you ever tried using ANC headphones? They'd be better described as noise-reducing. They can also be uncomfortable to some people when worn for long durations, and you presumably do want to let players in the same team communicate to each other.
Two theories: 1. Noise cancelling headphones don't cancel everything 2. They needed to be able to use mics, which don't work well with a lot of ambient noise.
They don't cancel well enough. You can still hear some noise. You probably can't identify what it is but it is enough of a signal to react to (spoiling your surprise play/ambush)