I feel this. I haven't made a friend in years. I'm lucky to have retained one or two from my younger days, but hell if I know how to make a new one. Sure would be nice. But no one ever sticks around. I always find myself wondering what makes me so off-putting, or maybe it's the fact that I have nothing in common with anyone. But you'd think surely there would be someone out there who was like-minded enough to actually hold more than a 5-second conversation? idk...
One thing I have noticed, especially online, is that more and more people seem to have some kind of social anxiety/shyness/lack of confidence etc. Seems like the more we rely on screens, the less comfortable we are with people. Go figure. But it may not just be you (or me) being off-putting; it may be that the other people we talk to feel the same lack of confidence in their own friendship-making abilities and it drives them to stay quiet. Somebody's gotta make a move, and hope for the best.