The old chestnut of towing causes extra wear on the brakes because of the extra load has raised its head again.
With a braked trailer the caravan brakes take the vast majority of the extra braking effect so the additional load on the tow vehicle is barely different to carrying an extra adult.
Also as the typical speed when towing is less than when traveling solo, the actual braking effect needed is reduced.
There should not be any significant increase in car brake wear, just because you tow.
Brake wear variation is principally dictated by the driving style and habits.
I don't fully agree with your theory, the towing car will probably be more highly loaded with equipment, the car will take a higher braking load initially, until the caravan brakes start to take the braking load.
I have noticed that cars towing , when braking will apply their brakes for a longer period slowing the outfit more slowly than a single car, which will brake for a shorter time .
I do know that the front wheels of my car show appreciably more brake dust when towing than, when solo.