Don’t forget, those soldiers were essential to the defense of Britain.
If they had not made it home the Germans would have had an excellent chance of conquering Great Britain. It was a near thing anyway, with only the RAF standing in the way.
That would have left the Germans with a single front war against Russia.
Russia would have fallen.
North Africa and the Middle East would have fallen.
Not really. They were only about 10% of Britain’s fighting force. Much more important to the defense of England was the navy and air force, which is why Churchill didn’t put large quantities of them at risk to rescue the soldiers. Keeping the Germans from landing (or as it turned out even trying) was much more important than turning it into a fight once they did land.
Hitler was not interested in invading Britain. But, what is true is that it helped the Brits easily handle the Italians in North Africa, which then made it necessary for the Germans to get involved in North Africa, which diverted crucial resources from Barbarossa.
The Germans had next to no surface navy and could not fight through the Royal Navy to land an army. Their only chance was to establish air supremacy over the Channel to keep the RN out. To do that, they had to defeat the RAF. Hence, the Battle of Britain.
Never have so many owed so much to so few . . .