They will stop showing up most likely.

I would also just stop asking these people out.

Me and my partner don’t meet with people that often but we meet with people that don’t do phones while we meet.

I think I would just ask people out of my house or if in restaurant I would finish up and leave.

The only friend that would do this around me got a rant or two from me. Basically told him I didn’t invite him over for that and he should be present if we’re together. He’s a great guy and actually changed his behavior after that.

Honestly, I wish that could become a cultural norm. As things are now it would be a kind of awkward request, but I bet it would really help if it were acceptable.

Make it understood that it's a theme party. As long as it's not a surprise on arrival. Promote it on the socials when you do the invite. It's not like you invite people individually anymore either. Its the 2020s, gamify that shit!

When I hear "gamify" or "gamification", I think 2000s, not 2020s.

I think norm should be asking people to leave if they cannot put the phone down.

Usually when people are staring at their phone while we're hanging out I pull out my phone and send them a text message.

It seems like it's punishing to people who are responsible with it. If you have issues with people showing up and not being away from their phone, then either talk to them or don't invite them. It's not your job to "fix" them from their habits. If you like them enough to be friends with them in spite of that, then why are you excluding them because of it?

Don't be passive-aggressive about it.