Spent the last year or so not picking up phone calls.

It's done wonders for my mental health and anxiety. I get a lot of robo calls, telemarketers etc. If I don't know the number I don't pick up. If I know the person, I make sure I absolutely am in the right mental state to speak at leisure for half an hour.

I never get thoughts like: "Oh, I wonder what this person must have wanted to say to me, must have been something very important and urgent" 😁

It rarely is. It's more likely something that they need you to do for them. It could easily have been a message. It should have been a message. They don't value your time or the tasks you may be concentrating on.

If it's an actual emergency, people will call your phone a hundred times.