The days of flashy websites with heavy graphics has passed and given way to content rich, easy to navigate websites ready for any platform. Nowadays it is very common for a user to search on a phone and later revisit the same pages on a tablet or traditional desktop. So website visitors need a common and intuitive way to get to the information they came for on any platform. This is called responsive design.
There are still needs to provide a robust user experience with intense graphics or a function packed mobile application. The art is to balance these strategically to maximize your service offerings. No one said it is easy, so start by understanding the benefits and downfalls of these possibly competing investments.