There are reasons people start chats like this, and those reasons aren’t going to go away, so this is going to keep happening whether it annoys you or not.
* They want to have a live chat with you and are trying to see if you are available for this. “Hi” -> “Are you currently available for a conversation?”
* A message that jumps right to the point can be considered rude or disrespectful, especially if the sender is going to ask you for something, and double if they are going to ask you for something difficult or outside your routine responsibilities. Culture, personalities of both parties, and the dynamic of the relationship between them all play a role here. Sometimes a person starting a chat feels they need to move slowly.