I’ve made classic marinara both ways and I actually prefer to use canned. Canned tomatoes are made with fresh tomatoes preserved at the peak of tomato season, and canning keeps the sauce very fresh and keeps all that flavour locked in. Also, they are canned with some salt and that always brings out their flavour. One thing I would say though is make sure you buy good quality San Marzano tomatoes. Your marinara sauce recipe from scratch is only going to be as good as the tomatoes you start it off with.