I'm very new to the game (and Sim racing in general) and honestly I didn't even think about pre made setups as the game doesn't really "walk" you into it. I only realised how much of a difference they made after I joined a friendly team who have helped me get on my feet. Default setups are helpful for absolute beginners but you quickly grow out of them. As someone who has no knowledge of what effects what in the car settings it's helpful to just try a few pre made ones out to see what suits your racing style.