Fiber maybe for some fastest backbone runs and longest runs properly protected and handled with proper care. But in many applications the main media is copper cable where the media selection is between unshielded (UTP) and shielded (STP) varieties.
I have some copper comments on UTP vs STP. STP is nice in locations where good electrical power grounding can be guaranteed (less than one volt potential difference). When used on those conditions provides good shielding.
STP on temporary settings where there are long power runs and maybe different power sources has some potential risks on ground loop current on cable shield and even risk of electrical shocks when having long runs between different locations. Ethernet over UTP is completely transformer isolated connection on both ends while with STP there is the extra shield that interconnect equipment grounds together (for both good and bad).
I have solved some audio+video+networking systems problems by changing from STP to UTP (or fiber).
I have had on my “ground loop problem solving tool-set” few UTP Ethernet patch cabled and RJ-45 F-F adapters so I can cut the ground on Ethernet connection when needed.