Because you still can write a letter stick in in the iggris koidesh or go to the ohel . And you can get a answer in different ways. Like a video,a letter,a dream, someone asking/telling you something . There are hundreds of ways ….
Those aren’t ways in which he’s alive, those are ways in which you choose to interact with him as if he’s alive. You could do most of those with Elvis if you wanted to.