It's always a good idea to decrease impedance, especially inductivity of 'earth'. In some studio recording applications, with scientific measurement stuff and in certain computing applications 'earth' is enhanced by introducing an earth mesh grid put on the floor, where each chassis ground and mains earth is connected to it. This creates a reference potenial of very low inductivity. This arrangement will also minimize potential drops between the individual devices, if a lightning hits the building.

If there are no separate 'N' and 'PE' lines in a factory, in can be helpful to add further earth wires, which are connected to and between as many machines as possible. When these additional connections form an idealized earth mesh grid, impedance, especially inductivity of 'earth' can be drastically decreased. This indeed can decrease unsane noise levels in a measurement application, which originally suffered from big errors.
Having a low earth impedance, especially low earth inductivity is the more important the higher frequent interference hits the arrangement. Especially cell phone radiation and similar can drastically increase noise levels and introduce lots of measurement errors.

Kai