Well, that's because the battle eventually took place in (mostly) France. But it's not as if that battle would not have eventually happened in the UK if the Germans had managed to gain air supremacy over the UK or if they had managed to pull a reverse Normandy. The UK could not have exited from the war at any time at all, their shipping would have been sunk and they would have been under siege from the moment they did so.
The larger cities were receiving a good number of aerial bombardments and V2's (ok, also a form of aerial bombardment). And then there was the shipping tonnage sunk with all hands.
War very much came to the UK, even if the eventual battle took place in France, Belgium, NL and eventually Germany (where whole cities had been obliterated).
Not so for the USSR, since it had been designated as "Lebensraum".
WW2 was an existential threat to the Soviet Union. It was so existential that this became the largest part of the identity of Russians.
But WW2 was not an existential threat to UK. UK could have exited from the war at any time. No battle took place on the soil of UK mainland.
I am not saying the people in UK did not suffer - they just did not suffer comparably to the people in the middle of the conflict. In a way the war was rather distant to the people living in UK.