I've thought this would make sense too and I feel like I'm missing something as to why it hasn't been implemented. Complexity perhaps? Interesting to note, tho

I've thought this would make sense too and I feel like I'm missing something as to why it hasn't been implemented. Complexity perhaps? Interesting to note, though, that we do have weak forms of braking that don't light up the tail lights - heavy engine braking in the case of manual transmissions, lighter engine-braking for automatics, and in the case of electric vehicles (at least a Tesla in my experience) the lights don't kick on from regen unless it's passed a certain deceleration level.