It causes more wear on your clutch and motor. I'd rather pay for new brakes than a new clutch or car. Sure it's necessary when going downhill, but the real mvp play is to keep enough distance and drive passively enough that you don't need pedals or motor brake. If you see a red light early, just go of the gas and let friction bring you to a stop.

Similarly I see a lot of impatient people overtaking one car at a time accelerating and braking all the time even on a motorway.