Scarifying and raking are sometimes the same thing, as a scarifying attachment can be added to a rake handle for the purpose of scarification.
However, rakes are more typically used for the less intensive lawn care processes of dethatching (to remove some thatch) and lawn raking (to remove moss and debris such as fallen leaves). Using a rake for scarification is not uncommon, but it can be tough, physical work.
If we’re assuming ‘raking’ means ‘dethatching’ or ‘lawn raking’, then it will have a different effect to scarification using a scarifier. Scarification will mean more thatch is lifted from the lawn, and the lawn will be dug up to a greater extent.
Neither scarifying nor lawn raking is better than the other. These two distinct actions are both ideal for achieving a particular end result.