It is a common argument on the internet that had Germany just continued bombing the British military aircraft industry and radars instead of redirecting the strategic bombing focus to terror bombing, that they would have won the air war over Britain. This subsequently would have supposedly allowed a Nazi invasion of the British Isles, as they now could have used paratroopers to secure strategic points as well as use bombers without hindrance to bomb the British fleet should they approach the German naval landing forces.

But I have read counter arguments that Operation Sealion still would have never been successful, even with the British airforce mostly gone.

The first argument is that it is not clear that Germany could have won the air war, even if it had stayed focused on military targets during bombing raids.

Furthermore the argument goes that even if they had destroyed the British airforce, that still did not mean that they could now just send the British fleet to the bottom of the English Channel. Germany had no real purpose-built naval bombers - it mostly used the He-111 and Ju-87 to do naval bombing, both which were not built for this purpose - and even if they had them, they still lacked the doctrinal experience to use them effectively. And even if all this had been true, Britain would have likely just staged a somewhat suicidal attack against the German invasion force and done enough damage to it that any further invasion of the British isles was impossible.

Last but not least even if they had managed to land a sizable force on the British Isles without it being sunk by the British airforce or fleet, their supply lines still would have been extremely vulnerable to British harassment attacks against German shipping. So Britain would still have been able to starve out the German forces over time.

Do note that I am merely talking about a successful "Operation Sealion" here. I have no doubt that Germany absolutely would have attempted it, had they had the chance to do so.

It is also no doubt to me that the British genuinely feared a German invasion of their Isles until at least 1941.