hi,

see data science and ai and ml both is emerging technology and have wide scope in the near future, thats why most of the top btech university started cse course with data science or ai and ml, but the salary structure is depends on the organization in which you work for, that why its not possible to tell that which of the position will have highest salary, if you want to make career in computer science field you need to be a quick learner  and adopt new technology, and this goes for all the techies who are working in industry.

data science is a course where scientific methods, statistical approach is use to make the model and progress of a scientific system, where al and ml is a computing term use to make system the ability to automatically learn and improve from experience.