Pros:
- HEALTHY!
- Save money on fuel and maintenance
- IDK, feel more in touch with the world?

Cons:
- Have to already be in decent shape
- Car drivers hate you on the roads
- Pedestrians hate you on the sidewalk
- Cities won't give you bike lanes
- SWEAT
- Seriously, you're gonna spend all the money you're saving on deodorant because you live in an area that regularly experiences highs of ~40°C during summer