All of the obstacles in that video are small and convex. This is the easy case of obstacle avoidance. Basically use modified steering behaviours. If that's all

All of the obstacles in that video are small and convex. This is the easy case of obstacle avoidance. Basically use modified steering behaviours. If that's all you'll ever have, then great -- don't build a system that you don't need. If you ever move to large non-convex obstacles, like a maze -- there will be mounting problems until it would have made more sense to use a navigation or path-finding.