In fact I believe the current A321 does not have the range for Almaty or Bishkek (routes that BMI/GB used to fly) without stopping en route. Likewise for African routes. BMI/GB used to stop in eg Tbilisi/Beirut/Yerevan and refuel.
The A321LR could open up routes such as Dar (economic growith rates v high), Addis (likewise), Astana and perhaps allow for eg Almaty to be more than x3 weekly. (Yes, that does reflect my personal travel requirements !!).
BA’s failure to service developing economy routes eg Dar is something I really do not understand and I find the lack of scrutiny from travel press puzzling. Saving grace is Qatar do service as BA codeshares many of these and are superb.