I have no idea what happens in Belgium, but nothing like that happens here in the US. They barely ask people to wear a goddamn mask, and they are all up in arms about it.
“That’s not approved!! Get out of here!”
Different things are happening
I don’t know the circumstances of the situation you mention, but it hardly qualifies as security theatre. Also, I doubt they screamed ‘not approved’ but I guess no anti-mask narrative sounds dire enough without a little exaggeration.