Landline: A facility to make & receive calls.
Line Rental: The physical line to your property that carries your broadband.
You are probably conflating the two. You obviously can't have a service without a line, but the Line Rental Saver scheme aside, no broadband customer has paid a separate line line rental for years, as it's incorporated into the single broadband cost. Even LRS is now ceased.
As for whether a separate charge is warranted for a landline is debatable. Some hear think it's perfectly reasonable. Others, like myself, would point to the fact that for decades, the landline was an intrinsic part of line rental. For me it's all smoke & mirrors that was started by Vodafone when they first started shouting loudly that they would no longer charge broadband customers for line rental. Of course what they meant was that it would simply no longer be a separate item on the bill, the price remained the same.
BT have taken that ball & run with it by claiming you can have cheaper broadband if you don't have a landline. This is of course another lie as broadband prices were never reduced. Instead prices remained the same with a landline fee added on top.
