Trailer brakes are NOISY! The magnets drag on a flat disc inside the drums and set up an annoying scrub and screech, and a lever arm applies the braking force to expand the shoes against the drums. they're also extremely sensitive to the amount of current applied to the magnet, going from barely slowing the trailer down to wheel lockup with just a tiny increase in voltage to the magnetic coils. I don't think Uncle Sam prints enough money to bribe me to drive a vehicle with all-electric brakes!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!