Hi, English isn’t my mother tongue so I was asking myself that question since I first encounted a w/… Back then I was like: “What tf does ‘w slash’ stand for?” And when I found out I was like “How, why, and is it any intuitive?” But I never dared to ask that until now
For instance, if you want to text someone “I have an appointment with the Dr. at 11 on Tuesday”. Depending on the dr’s name it might be more to type than someone cares to, especially if it isn’t the most pertinent piece of information.
If you are gonna put Dr then odds are you’ll follow with @ and it’s a non-issue.