> Earbuds stop this practice dead in its tracks. You can't deny that.

Yes it's a signal. For you to go find someone else to talk to :)

That doesn't mean I'm antisocial, there's just places where I go to be open to talk to people. Like bars, meetups, stuff like that. And places where I'm just to get from A to B and I don't want to. Usually when I'm in public transport I'm going to/from the office and I'm stressed because I deeply hate working in the office since Corona (no more fixed desks etc). So I need my space.