When I was a smoker I found that the smoke pit was the only area in the company where senior leadership and new, low-level hires would openly converse without the typical formalities. This often lead to people being pulled into projects they wouldn't typically have access to.

For me, I often received extremely valuable input from folks in other departments for the projects I was working on -- typically people in production had the most innovative ideas compared to that department's leadership.

Nicotine temporarily lowers the effects of some forms of anxiety. Socialising can be scary for people.