Companies aren't going to ignore "free information available at your fingertips" about the candidates they hire.
For example a problem candidate may have easily accessible "red flags" on their social media such as racist stuff and drug use.
They could "save" themselves some costs and future problems by knowing that ahead of time.
When companies are trying to optimise their hiring process they aren't going to ignore free additional information about the candidates, they want every last piece they can get their hands on so they can (at least in their mind) make the optimal decision.