Why A wire is only a good ground at DC and low frequencies. At RF, a ground conductor has inductance and can be an appreciable fraction of a wavelength long, so it presents a high impedance. Current flowing through that impedance develops significant RF voltage on the chassis or 'ground' connection, and touching it gives an RF burn. The cure is short, wide, low-inductance bonding straps, or common-mode chokes and counterpoise to keep RF off the equipment.
Watch out The resonant ground rod choice sounds plausible but it is the wire between the equipment and the rod, not the buried rod, whose length and inductance matter; flat braid is actually better than round wire because it has lower RF inductance.
Ground wires can be hot at RF: short and wide equals low impedance, long and skinny equals RF burns.