I can only see myself using this if they make new titles available between the time of the theatrical release and the BluRay release.
I don't go to the movies much - I saw The Boy and the Heron last month, but before that was Tenet. Sometimes I will want to watch something that's in theatres but not on streaming or BluRay - this could fill that niche, if they wanted it to.
If not... I can wait and download it my usual way.