Yes, the UK approach was (and perhaps still is) astonishing.
To the best of my knowledge, the UK have been the only country to do NO checks on incoming passengers since the epidemic/pandemic was declared. It is most puzzling as to why they felt it was unnecessary to do at least a rudimentary control. I took several flights at the end of March and was checked all the way through until arriving at at LHR to nothing. Zero. Zilch.