They are trained to know what to look for and their job is reading policies and understanding coverage.
2. They work for you
If you hire them they work for you, not for the insurance company.
They get paid a percentage of what they recover for you, typically 10%.
4. Detailed evaluation
They look at your structure with a trained detailed eye. They fly drones over the roof to uncover damage that could not otherwise be seen, etc.
5. It's not too late ...
If you have already been paid or already negotiated flood for example, they will only be paid on the additional amount they recover.