It's not necessarily about the time it takes to type the type definitions. static typing leads to developers trying to represent the "real" world in a bunch of categories and arbitrary boxes. Thats not necessarily a good thing because you can loose much time in bike shedding discussions like "Is a person class still a valid person class if it has no Surname" which do not provide actual value to your product. Recommended watch: https://www.youtube.com/watch?v=YR5WdGrpoug