A narrow viewpoint: Looking at the IV percentile to gauge the option premium "relative volatility", is useful when deciding to enter specific trades, such as Iron Condors. Say, if 52 week IV percentile < 20% (pick your own comfortable number) , don't enter, as the credit will be low relative to the risk of Volatility increasing against your position. The idea, assumes the IV will be mean reverting, which may or may not occur in your timeframe. This seems logical and is touted by Tom on Tastytrade.