Just like how carbs can be categorized by good (complex) and bad (simple), fats are another necessary macronutrient that can be argued. Monounsaturated fats actually help lower unhealthy cholesterol while providing us with energy. Getting enough dietary fat can benefit many but especially those on the keto diet. Because it's low carb and high fat, eating the right kinds of fats is crucial for transitioning into a state of ketosis.
Online nutrition coach Amber - FitnessFT shared a helpful breakdown on Instagram of which kinds to look out for, regardless of what your diet is: