I agree with your thought process. Factoring in antenna type and reflections also causes difficulties when explaining concepts like super position. The sinusoid is a good illustration of what a given receiver might detect at some location (X,Y,Z). A more accurate way to show that may be a light source fading on and off to match some frequency (below THz). Then factoring in the speed of light, at time zero, the light will be off, at some arbitrary time 1, the light will be illuminated at 0.25 (scale goes up to 1 here). The light energy peak at time 1 is at the light. Then at time 2, the light goes up to 0.5. That means that the 0.25 light is now 1 unit away from the light while the 0.5 is at the light. Step to time 3 and the light goes up to 0.75, meaning 1 unit from the light, the light is at 0.5 and 2 units from the light, the light is dimmer at 0.25. This repeats with the light hitting 1.0 then falling back to 0.75, then 0.5, etc. The movement of light is key and I think that's what is often either misunderstood or just not considered enough.