Well mostly true. You can replace an inefficient (turns power into heat) antenna with a more efficient antenna which will then radiate more. And some frequenc

Well mostly true. You can replace an inefficient (turns power into heat) antenna with a more efficient antenna which will then radiate more. And some frequencies are regulated by effective radiated power, where they basically care about the strength of the signal in the strongest location, so a more directional antenna could push you over the limit.