The efficiency gain vs time invested is not exponential. It's linear at best and plateaus after about 5k hours. It is this plateauing of the curve that is the biggest reason power Excel users move to R or Python. That was certainly my experience after eeking everything I could out of Excel in 15 years of trading floor fixed income. A visual 2d paradigm is excellent for quick productivity but is severely limiting as complexity and data size rises. Even with VB.