Supporting adult dc with friendships/social life/loneliness

[dancingkween]

Not sure where was best to post this but hoping for some help.
DC is late 20s, has a few friends but they're flakey - too busy to do anything or cancel last minute. DC lives alone, works full time (with much older colleagues) and doesn't date.
DC has mentioned to friends before about how they feel but nothing changed. I have suggested joining a club or group but doing that alone is something DC doesn't want to do (tbh nor would I).
What on earth can I do to help. I'm so worried.

You say DC works ft but what about the weekend? Gym? Running club? Volunteering?

Volunteering might be a good shout, I hadn't thought of that. Thanks!

There are various meet up groups on Reddit for different locations. They organise a pub crawl or frequently board games events where you can play a variety of different games. He could look at meet ups?
That's not quite the same as a hobby.

I know someone in their 20s who moans incessantly about their lack of fun and friends but can't get his head around the fact that as an adult if you want fun you have to plan it and if you want friends you have to put yourself out there. (And believe me I've explained this many times) - it's definitely worth mentioning imo, though I know it's not the same for everyone.

I have loads of long term friends through hobbies but you cant force it if DC doesn’t want to.