I’m not saying they can’t move on, i’m saying they aren’t interchangeable. If we like going to art fairs together and you move to California and I start going to art fairs with someone else and don’t miss you - we were not really friends.
I had two roommates in college. I still miss one of them. We moved on to different lives and she can’t seem to stay in touch, (I refind her every decade or so, we catch up, she vows enthusiastically to stay in touch, she succeeds for a week or two, then silence....) but I still miss her. We were friends. The other one was a pleasant and agreeable person to share a room and a conversation.
there is a man I am “still” friends with, even though his wife is very opposed to him being friends with women and cut off our communication years ago. I know this, because I saw a sale listing that looked like the seller was him. I couldn’t resist messaging, and identified myself and asked if it was him. His response was (in summary, but with more length and concern) yes it was, and was I ok, and was my family ok, and did I need anything. And I replied “we’re all good (one or two sentence updates on each person) I was just wondering how you and yours were.” And he replied “fine.” (And clearly still married - but also clear that he remembers me and still cares enough to want to come through in an emergency.)