>> Reflecting on my own experience - frequency of contact (if I see them once a year, can't really count them as close friends)
I think this one is interesting. If you saw them daily for 20 years and then transitioned to once a year are they automatically not close friends? Even if they satisfied the other criteria (like you could turn to them when you are facing a serious problem, you have deep conversations on that annual meeting because you are comfortable with them, etc)?
I'd say we need a more analog definition than a binary one.
The term 'close' friend at least to me means close. Either in physicality or depth and regularity of contact.
Only talking to them once a year, even in depth is more like a semi-close friend. They are not there to help you with the day to day issues that you may not even realize you're having.
I think this one is interesting. If you saw them daily for 20 years and then transitioned to once a year are they automatically not close friends? Even if they satisfied the other criteria (like you could turn to them when you are facing a serious problem, you have deep conversations on that annual meeting because you are comfortable with them, etc)?