50k is nothing, ICE cars often go longer than that without new brake pads. Had my ICE sedan for five years with no sign of brake squeaks yet. Never thought about brakes when I lived on a huge hill either.
You should never ride the brakes for minutes at a time! Even if didn't care about wear, the main problem is they will overheat and become less and less effective so if you suddenly need to brake harder during that downhill, you may have little to no braking power.
Always use engine braking if faced with a long steep downhill. Use the brakes occasionally to modulate speed but never ride them continuously for a prolonged time.