It's not. And modular walls are quicker than chain-link. Army SF commonly uses framed plywood walls with locking, thick metal drop hinges on each side, roughly how a ranch gate works.
They're modular so that they can be quickly re-arranged, not to hide from satellites.
This used to be an important factor when you didn't want 'stuff' to be seen by satellites, needed to setup and take things down quickly.
I don't know if it's still a factor today.