I don't doubt that the screenings are security theater, but it is impossible to know whether anybody was scared off from even trying. A 10% or even 5% chance of getting caught is deeply concerning. It risks not just you, but everybody else in the plot.
It could well be zero: the turrurists aren't dumb and they also know it's security theater. But I have to admit that I genuinely do not (and cannot) know.
What changed in 2017? They stopped publishing the results of the testing.