The ID check is revenue management, the magnetometers are to make you feel safe against terrorism. They happen at the same place in the airport, but they are totally different things instituted for totally different reasons.
Since restaurant patrons aren't avoiding restaurants due to terrorism concerns, there would be no need for a security check. Revenue management is, however, broken. (You can't eat at your neighborhood restaurant anymore because tourists are buying all the seats from a bot.) So that's why the ID check is necessary.
I'm not saying that restaurants should do this, I'm just proposing a system that would actually work. Most likely, nobody really wants to solve this problem; huge banks like Amex can extract an extra $700 a year from people that care.
Since restaurant patrons aren't avoiding restaurants due to terrorism concerns, there would be no need for a security check. Revenue management is, however, broken. (You can't eat at your neighborhood restaurant anymore because tourists are buying all the seats from a bot.) So that's why the ID check is necessary.
I'm not saying that restaurants should do this, I'm just proposing a system that would actually work. Most likely, nobody really wants to solve this problem; huge banks like Amex can extract an extra $700 a year from people that care.