In short, it's more important to use a dict if you need key/value pairs, while lists are great if the value is the actual entry. Doesn't really matter. If a dict makes it more readable, you should do that - especially since you know you are going to need other keys.

Why use a dictionary instead of a list?

You would only use the Dictionary if you needed to map (or associate) meaningful keys to values, whereas a List only maps (or associates) positions (or indices) to values. For example, say you wanted to store an association between a person's age and their height.

What is an advantage of using dictionaries instead of using lists?

It is more efficient to use a dictionary for lookup of elements because it takes less time to traverse in the dictionary than a list. For example, let's consider a data set with 5000000 elements in a machine learning model that relies on the speed of retrieval of data.