Wouldn't it just be easier to...

Hi, James. Sometimes it is indeed easier to make a class, but sometimes it makes more sense to use a pseudo selector. For instance, if you have a long table of things and you want the last row to have a different colour, you could create a class, but if you ever have to update the list by adding more thing on the end in the future, you'll have to remember to move the class to the appropriate list item. Using :last-child here is like a 'set-it-and-forget-it' kind of option. Similarly, you can use things like :nth-child(even) to alternate background colours of table rows for readability without having to worry about adding a class to every other child element.

It's okay to create many classes, but in the same vein, you don't want to litter your HTML with unnecessary classes as your code can quickly become unmaintainable. The goal is to have your code with as little repetitiveness as possible, and using pseudo selectors allows us to do this quite easily.