Something that I've found useful when meeting someone in real life, I take an old phone that's only capable of making calls. That way I avoid any possible communication issues, but I don't get distracted at all.
The problem is that people under the age of 40 or so don't communicate via phone calls in the first instance. So a phone is not a means to communicate with them and you don't avoid any possible communication issues. Your lunch meeting is telling you on Slack that they're going to be late. You think you have no 'possible communication issues' but you're mistaken.
Your lunch meeting sends you a message via WhatsApp, but you don't receive the message because you don't have WhatsApp installed.
They think you've seen the message, you don't know they sent anything, neither of you realises, they don't turn up, you leave.
They message you again, you don't reply because you still don't have WhatsApp, and the two of you assume the other isn't interested and you lose touch.
1 year later, you install WhatsApp and it delivers the message from your lunch meeting.
If only you'd known! This happened to a friend of mine.