They were in the war from 1939 to 1945 and had less casualties than the United States who was in the war, effectively from 1942 to 1945. The British took part in no major offensive operations or invasions outside of North Africa before the US entered the war, and then every major operation was in conjunction with the US and allied divisions.

It's not a disservice to say they sat it out, it's facts, they were playing a defensive war of attrition against Germany. Does that mean they wouldn't get bombed? No. Does that mean their ships wouldn't get attacked? No. Does that mean no British person died, just that they weren't really interested in fighting Germany on mainland Europe unless they had other people to do the majority of the work.

Over half their army consisted of colonial or Commonwealth troops. Over third of all their casualties were from either the commonwealth or colonies.

More Soviets soldiers died in Operation Bagration from combat than British from all causes including British civilian and commonwealth combat personal combined. 2,000,000 Bengali died of starvation because of British war policies that prioritized denial of food to the impending Japanese invasion over the people living in the area.

They were as passive as they could be, you act like responding attack = offensive action. They minimized their casualties until someone else came along and held their hand or just did the work themselves. The Soviets would be marching into Paris if the US hadn't come along and held the British hands in Italy and France.