Nobody is going to care about your scenario.

(1) Passengers can't "see" the kind of security measure you describe. So, it doesn't benefit the politicians. Hence, it will not be done.

(2) The government is obsessed with security on airplanes. They do not care one whit about security at airports. For example, they apparently believe you can buy liquid explosives disguised as water in the "sterile" area of the airport--that is why they do not let you carry on water that you purchased airside. But how did they allow us to get into a situation where they believe airport vendors are selling liquid explosives disguised as water?!? And why do they allow the airports to continue operating if there is such a danger to the airports themselves?