Ephemeral House Insulation Impact?

People repeatedly call for the UK's leaky homes to be better insulated. It appears, however, that the effects on gas consumption of loft and cavity-wall insulation, are only fleeting (https://www.theguardian.com/environment/2023/jan/01/rebound-effect-cancels-out-home-insulations-impact-on-gas-use-study). The study, in England and Wales, found that the energy savings completely vanished with 4 years. This 'rebound effect' on energy use may result from changed behaviour cancelling out the reductions in gas use. Fitting insulation often occurred alongside building house extensions, requiring extra heating. Indeed, if a conservatory was fitted, the energy efficiency improvements disappeared within a year. Having said all this, it doesn't mean that house insulation is a waste of time. Building an extension or adding a conservatory, might well increase the number of folk able to comfortably live in the property. Such additions are, however, less likely in the case of rented accommodation.