Twist rate is only part of the equation. The length of the bullet plays a part regardless of the weight and you can also help stabilise longer and heavier bullets in less than ideal twist rates by pushing them faster. Longer and heavier projectiles can also destabilise at longer ranges as the velocity drops. I've had exactly the same projectiles shot from exactly the same twist rates at the same velocities and one will be under stabilised and the other will be fine.
As Darren said the faster the twist rate the faster the barrel wear. When you think that projectiles can crack 200,000rpm you can see why things wear out fast
There are very few things on earth that only have a lifespan measured in seconds. Barrels are one of them. Therefore if you value a decent barrel at $1000 and have a 2 second lifespan (typical modern magnum) you are paying $1.8 million an hour to shoot