RADAR was one of those inventions that they thought was completely revolutionary, and it was, but was far less "unique" than the creators originally believed.
The large air and naval search arrays all over southern England had been spotted by the Germans even before the war and they accurately worked out what they were for and reverse engineered them purely from reconnaissance photographs.
The special thing about the RAF at the time was that they'd managed to make units small enough to fit on board planed which was the big advantage they hid as being carrots.
Funny story, so convinced were the British that the concept of RADAR couldn't have been copied by Germany that when they surveyed the Graf Spee while in dock at Montevideo, with the RADAR antennas, identical to those on British and American ships clearly visible they still didn't believe the Germans could develop the technology.
The idea is called Hypernormalisation. Everyone knows what they're being told is a lie, most don't care, some do but a powerless to do anything about it, the rest are actively perpetuating the lie.
Excellent documentary about it by Adam Curtis which is watchable here: https://m.youtube.com/watch?v=Gr7T07WfIhM