What is so bad about just going out and doing sports with people and having real contact?

I guess that everyone is different. In my case I really enjoy participating in HIT workouts with people; the group competition drives me to push myself.

That's one of the reasons for having better results in a marathon than during training: group competitiveness

The second benefit is also obvious to me: socializing. Just the fact of doing sports together gives you a sense of bonding, of going through similar pain and succeeding.

One can argue you can achieve the same with VR meanwhile for me is just a poor replacement.