Note high efficiency occurs when Rs<<Rl.
P = I^2 * R therefore low Rs = low lose and high Rl = higher power out.
Simple enough with resistive circuit.
60 years ago neutralize the circuit. Today conjugate the reactance. In neither case are we setting Ri = Rl.
Food for thought.
In the last post I said "TUNE" the ground and "TUNE" the antenna.
Would be better to say NEUTRALIZE the circuit reactance.
R + i0 feeding R + i0 provides maximum power transfer.
Low R feeding high R for best efficiency.
Years ago the device was named a tuner and that is how we describe it.