I didn't see you ask, "Are you happy?" before your sentence, "he confesses to me" that he hasn't dated in years. "Confesses" explicitly means he thinks he has done something wrong. Why is not dating wrong?
There are many paths in life. Kids; no kids; marriage; single. There are also timing issues. Corporate career early, late, not at all. Marriage / kids early or late. There is NO single right answer for everyone.
You ASSUME that the mid-20th century US norm of: go to college->get a good job->get married->have kids is the correct path, and your friend must "confess" to not following that path.
I graduated from college a long time ago. As did a brilliant college project partner. I "followed the path" leading to a long and expensive divorce and child custody battle. I have a wonderful son from that horrible marriage. My best friend/second wife, and I look forward to attending our son's wedding later this year.
We live in our dream city in a great condo. That is the good side of not selling my company to a big firm and being forced to move to a lower-priced business city.
My buddy built his retirement fund early, got married later, and had a kid later. He is already retired. Has a huge real estate portfolio. In a city I dislike for multiple reasons.
If our kids have grand kids, I'll still be young and fit enough to play with them. He won't be, but he can take them on trips out of my financial reach. I quite possibly will live to see great grand kids. No chance for him. We're both immigrants. He will be able to afford his family opportunities I can't, if he wants.
We were two mid-20s engineers who took very divergent paths 35 years ago. We're both happy with our decisions now. There is no one right answer on how to live a life.