I agree that in the coax side, there is no real 0V because the current has a
standing wave. But the transceiver has a DC power supply (normally 12V) that
is controlled or modulated. One side of the power supply is regarded as 0V
and connected to 0V rail of circuits. The modulated side is the RF live that
is connected to the centre contact of transceiver output connector.

In theory, while transceiver is transmitting, if I touched the outer of the
output connector, I would not expect to get a shock or RF burn. If I touched
the centre contact of output connector, then I would expect to get a shock
or RF burn. Admittedly, I could touch the outer and find that I am close
enough to the centre contact for RF to capacitively couple into me. In real
life, I would never touch the output connector while the rig is
transmitting.

Does RF live and ground not exist on the output connector of the
transceiver?