Why is it so hard to make friends these days?

Call me close-minded, but in the last 5 years I've noticed that it's gotten alot harder to find and make genuine friends anymore. My interests just don't align with alot of others at all, which makes sense. I was never the most popular kid in School at all, but I always found it hard to make friends. It's depressing because all the friends I had for a long time are finally moving on with their lives, while I'm still going at a turtle pace. It feels like I'm stuck, and can't even find new friends to compensate for my old ones leaving.

Is there any advice from others who have felt the same way in the past? Or maybe even are feeling the same way now? How can I get myself out there better?