I wouldn't discount that last reason. There's some research suggesting that friendships between coworkers can greatly increase worker engagement, productivity,

I wouldn't discount that last reason. There's some research suggesting that friendships between coworkers can greatly increase worker engagement, productivity, and satisfaction.[0][1][2] And a self-report study from LinkedIn suggests that workers perceive workplace friendships as beneficial for both themselves and their work, for what that's worth.[3] Of course, it can also blow up in your face and do the opposite, occasionally slowing down more productive workers as they match their speed to those of their less productive friends when it comes to individual work.[4] That study looked at fruitpickers, but it could be relevant to the tech industry as well. Paradoxically, at least in the US, we're seeing a trend towards fewer workplace friendships and greater detachment.[5] I/O (industrial and organizational) psychologists have a lot of interesting interpretations for those trends. Almost across the board, employment is far more transitory today than in past decades, so there's less pressure to invest time in meaningful relationships at work. And we're so connected nowadays that it's easier than ever to preserve relationships in some form (regardless of whether they're preserved, or we just believe they are), so we don't feel the need to generate replacements as much. Having done a lot of freelance work myself for a couple of years, if I'm being entirely honest with myself, this is one of the disadvantages at times. I enjoy getting to work on different projects, but there's something to be said for getting to focus on something with the same team. Even if open offices and talkative coworkers can get in the way at times :). 0. https://hbr.org/2013/07/we-all-need-friends-at-work https://hbr.org/2013/07/we-all-need-friends-at-work 1. http://www.gallup.com/services/178514/state-american-workplace.aspx http://www.gallup.com/services/178514/state-american-workpla... (behind a form) 2. https://www.fastcompany.com/3051290/why-having-friends-at-work-is-so-important https://www.fastcompany.com/3051290/why-having-friends-at-wo... 3. https://blog.linkedin.com/2014/07/08/work-bffs https://blog.linkedin.com/2014/07/08/work-bffs 4. http://www.lse.ac.uk/website-archive/newsAndMedia/news/archives/2010/02/friendsinworkplace.aspx http://www.lse.ac.uk/website-archive/newsAndMedia/news/archi... 5. https://www.nytimes.com/2015/09/06/opinion/sunday/adam-grant-friends-at-work-not-so-much.html?_r=2 https://www.nytimes.com/2015/09/06/opinion/sunday/adam-grant...