Importance of Implied Volatility in Option Pricing

An analyst is evaluating a European call option for a stock currently trading at $50. The option has a strike price of $55 and expires in 6 months. The analyst notices that the implied volatility for similar options in the market is 20%.

Knowing that implied volatility reflects the market's expectations of future volatility of the underlying asset, the analyst contemplates how it affects the option pricing compared to historical volatility and actual price movements.

What is the primary reason implied volatility is important for option pricing?