Smart theaters, restaurants, etc., would invest in a “phone-free experience” with Faraday-cage wallpaper. Fine chicken-wire mesh would work well.
The LIRR has phone-free “quiet cars” for those who don’t want to be annoyed with someone whose phone is seemingly permanently affixed to his/her/its ear. I’m amazed businesses don’t do similarly.
I mean, some restaurants are “family friendly”, but if you’re on a romantic outing and don’t want some anklebiter pulling down a tray of thick-shakes right next to you, you can go to places which are… “family-hostile”? :smiling_imp: Some do not have kiddie-seats, boosters, or highchairs, and make it clear that kids are not welcome. Not that they hate kids, but letting the larvae of inconsiderate parents roam free to pester everyone else in creation can absolutely ruin a romantic mood.
Similarly, they should be able to absolutely prohibit cellphone use, period. If it means chicken-wire wallpaper, metallised-window-tint, etc., to block cellphone signals, so be it. Like with smoking nowadays, if you need to, go outside.
And failing that, hey, why not cellphone-blockers?