1. There exists incremental compilation which reduces waiting time to run a unit test to a bare minimum.
2. There exists a whole set of latencies in deployment beyond compilation that also apply to interpreted languages.
3. Developer productivity is not measured in lines of code, but in delivered business value and as such is influenced by many other factors beyond how much time you waste on context switching during compilation. That one is usually pretty minor one: you are the first person in my 25 years of career in IT, who mentions this. Maybe you have some specifics in your field of work where it becomes important, but majority of the industry doesn’t think of it too much (and there is incremental compilation).
2. There exists a whole set of latencies in deployment beyond compilation that also apply to interpreted languages.
3. Developer productivity is not measured in lines of code, but in delivered business value and as such is influenced by many other factors beyond how much time you waste on context switching during compilation. That one is usually pretty minor one: you are the first person in my 25 years of career in IT, who mentions this. Maybe you have some specifics in your field of work where it becomes important, but majority of the industry doesn’t think of it too much (and there is incremental compilation).