Of course, those ideas were compulsory from the 1990s under EU Laws - did R governments of the day be bothered?
Not many properties have the radiators that will accommodate any new ideas pushed onto owners, so the £5,000 for each won't go anywhere near the over all costs. And when an attic has too much insulation, the rafters are in danger of rotting due to condensation. What will that cost and how many owners realise and go into the attic space to check?
Houses need to breath: hence the air brick between two layers of inner and outer bricks!