You're missing the value of these things in identifying bugs. When you subtract a number of seconds from a temperature, you'll be glad for the compile-time erro

You're missing the value of these things in identifying bugs. When you subtract a number of seconds from a temperature, you'll be glad for the compile-time error. There also doesn't have to be a runtime cost, as in C++ (and languages supporting value type instances) they can either be type-erased or cost no more than an integer.