Depends if you are delivering food or cycling for sport. The dedicated devices have extremely good battery life (around 20 hours screen on with gps), have connectivity for ANT+ accessories, have large physical buttons designed for use while cycling with gloves, have reflective displays with great visibility in the sun, etc.
Sure, you don’t _need_ them but they don’t cost very much compared to your other gear and the minor improvements stack up.
Sure, you don’t _need_ them but they don’t cost very much compared to your other gear and the minor improvements stack up.