One of the things i like best about traveling is that i have the time and mental energy to engage with the people around me. I eat at restaurants, i go to bars, i listen and share stories, i'll contribute to the local economy and perhaps put a smile on someone's face.
When i am working i suppose you could say i am contributing to society, in the sense that i am helping to build some software that performs a function our customers appreciate. But most of our customers don't live in my community. And even if they did, i'm not really employed to serve those customers, i'm employed to increase growth so that the company will make more money for its investors. Trickle-down theory says that's still a net contribution to society, but it feels very abstract to me.
Meanwhile, when i work i am too exhausted to spend any of the money i earn doing those things that i would when i travel - i don't spend money at local businesses, i don't talk to other people in the community, i just go home and sleep and go back to work again. It's the life most of us are forced into to survive, but i wouldn't really call it contributing to society, or at least not in as direct a way that people do when traveling.