I've written about this before.
I'm lucky - I have lots of friends. I had a great Italian evening this last Sunday where I cooked for 12 friends - it was great fun and good to be with so many people I know.
But so many "friends" are so lousy at keeping in contact. I invite them to meet up and hear nothing more from them.
Well, my focus is on those who want to be around me from now on. The others who hear less from me? I'll touch base now and again, but they can assume from the less effort on my part that I have taken their lack of interest as meaning they regard me as peripheral. And hence I will do the same.