Something that often happens with men: they tend to (on average) not be as big social butterflies as women, and so any past friends they had fade into the background/disappear. It takes time/effort to keep relationships going.
"Why most men don't have enough close friends"
* https://www.ctvnews.ca/lifestyle/why-most-men-don-t-have-eno...
"Men have fewer friends than ever, and it’s harming their health"
* https://www.vox.com/the-highlight/23323556/men-friendship-lo...
"Men’s Social Circles are Shrinking"
* https://www.americansurveycenter.org/why-mens-social-circles...
"Men struggle to keep friends — and it’s hurting their mental health"
* https://globalnews.ca/news/6112225/male-friendship-mental-he...
"More than 1 in 7 men have no close friends. The way we socialize boys is to blame":
* https://www.latimes.com/lifestyle/newsletter/2023-10-10/more...
Also, with people having fewer children (if any), support structures toward the end of life are getting smaller and smaller.