I recently came across the below infographic, lovingly put together EveryCloud, and I think it does a great job of showing where email can have serious advantages over other tactics.
Email marketing (aka E-DM, EDM) has a pretty poor reputation. When coaching in digital marketing quite often this tactic is overlooked, and when I bring it up I often got a negative sceptical reaction. But actually, email marketing is often the unsung hero. Done well, it can provide extraordinary results, but it's not without its challenges.