Most people today (a vast majority) do not think sound ruined film, but there is that old school (and I mean old school) fringe that still clings to that notion. I remember having to watch a documentary in college about how the coming of sound was a aken to great cultural tragedy. I remember thinking "huh?" I didn't think Blackmail felt all that much like a silent film. He moved into sound pretty well, as you say. Interestingly enough Rich and Strange (isn't that his next film?) felt more like a silent film that a sound film. Rich and Strange was definitely a step back, in many ways.