It may be beneficial for some, but not everyone. Also a large part of therapy is having an isolated environment where you can openly talk about anything that you wouldn't ever share with anyone else. A group of friends is often not that environment.

> Or is it just the safe thing to say without sticking one's neck out?

If you want to stick your neck out in that situation you could offer making a therapist appointment for that person. It lowers the barrier to getting help a lot and imho feels more understanding and supportive than trying to cheer them up or whatever else one might come up with. YMMV of course.