My wife's explanation for that (and I agree) is that the British actors and actresses are real people, pudgy, thin, gangly, teeth as grown, hair style askew, and all the variations of people. The Hollywood/TV Land actors are all alike -- cookie cutter perfection. Therefore, acting ability takes precedence over appearance alone.
Yes.
I agree. In addition, in the UK actors and actresses move amongst TV, theater, and film.
Insightful.