There are a lot of critical situations where humans can't help. A nuclear disaster is too radioactive, a bomb is to risky, a fire is too heat, etc. But there's still help needed. And when humans can't help, robots do it. They aren't organic, so they can survive high radioactivity. They don't have a life, so it doesn't matter when they explode. They can be made of material that can survive high temperatures, so that they can't melt.