It's not the only benefit, but it's the only one that you can't get in some other way. I suspect that very few people -- even people who love their jobs -- would continue working in them if they weren't getting paid.
Sure, the same is true for me. But that's also a need that can be filled without working for someone.
I think what we're talking about here is having a sense of community or at least human to human interaction. I can think of so many ways to get that without the obligations that come from having a job.
I generally enjoy my job but that is far from the main reason I do it. If money was not an issue, there are so many other things in life I would enjoy doing far more not to mention enjoying the general freedom that comes from not needing to work.
"No person is an island". I hate quotes like this, things that have the veneer of truth without any actual corroborating data. I am a textbook introvert, I get no greater joy and contentment when spending a Saturday morning pursuing a personal project solo style.