If you look at the history of these sorts of franchises, they have shown an ability to work on both TV and the big screen. For example, while comics franchises like Marvel and DC have expanded from print onto both the big screen and the small screen, the Harry Potter universe has remained more contained. Of course, there is less ultimate material to work with so far in J.K Rowling’s imagined world than there is within entire comics brands. Plus, the famous author has been busy getting a stage play and the Fantastic Beasts movies off of the ground.
Source : https://www.cinemablend.com/television/2466898/daniel-radcliffe-has-a-great-idea-for-a-harry-potter-tv-show