Your suffering from survivorship bias, and you also seem to be talking from the perspective of a colleauge at the same level or near enough as the new employee.

Your suffering from survivorship bias, and you also seem to be talking from the perspective of a colleauge at the same level or near enough as the new employee. Managers and above want people who dont really know their rights, have the energy and willingness to just do the job. They also assume that younger people have better skill sets. All things equal, younger people cost less.