If you are comparing 2 values, sure, maybe. But 40% versus 60% still won't be the most obvious thing other than "60% is larger", understanding the magnitude of the difference will involve more thinking, flat out. Taking more mental processing power to understand a visual chart is a bug, not a feature!

At this point you may as well write it longhand, "X is much larger than Y". Since promoting anything less than maximally accurate beliefs is an act of sabotage on your fellow human beings, you have to ask yourself why are you using a pie chart - because it's not to provide value for users.

That's a really extreme way to interpret what I said.