Volvo's selection of engines in the UK has always been lacking. Tbf it could be due to an actual technical issue with adopting the drivetrain to right-hand-drive car, but in general I see that many manufacturers just pick a few engines that they think the British customer will like and that's all you can get, while people in France or Germany get the full choice of all drivetrains. UK vs US is even more funny because it's extremely common to see cars which are only available with a diesel in the UK, but only available with a big petrol engine in the US. Again, it's based on what the customer supposedly wants.