Maybe I agree if by go away you mean don't really use it for pricing derivatives for real. However it's still a very useful intellectual tool to understand how to generate a price for a very simple derivative.
As an analogy in high school physics they give you a problem like someone 2 meters tall shoots a gun and the bullet is moving so many meters per second, how far does the bullet go before it hits the ground. You use your formula for gravitational acceleration and figure it out, and Yeah! you get the right answer.
But you can't use this formula if you really want to calculate how far the bullet goes. You have to take into account air resistance and then you need differential equations and you probably need to approximate an answer with a PDE solver.
That's just the difference between a tool to explore foundational concepts and something that attempts to be actually be useful in the real world...
As an analogy in high school physics they give you a problem like someone 2 meters tall shoots a gun and the bullet is moving so many meters per second, how far does the bullet go before it hits the ground. You use your formula for gravitational acceleration and figure it out, and Yeah! you get the right answer.
But you can't use this formula if you really want to calculate how far the bullet goes. You have to take into account air resistance and then you need differential equations and you probably need to approximate an answer with a PDE solver.
That's just the difference between a tool to explore foundational concepts and something that attempts to be actually be useful in the real world...