I think there are a number of reasons:
Firstly, when the British empire was disbanded people in the former colonies were offered British passports. This lead to lots of immigration to Britain from places like Jamaica, Africa and India and the big cities in the UK became a mixing pot of different cultures and nationalities who brought with them their own music, which was picked up and modified by uk artists.
Freddy Mercury (frontman of Queen) was Indian and a lot of the bands you mention have strong Jamaican influences in their music.
Also, the UK may be more liberally minded than the US, so are probably more comfortable listening and watching new bands and new types of music. idk
The uk also has nationwide radio stations so everyone in the country could potentially hear new music from another region, whereas the us has mainly local stations where bands may not be able to get their music heard nationwide and instead may have only got their tracks played by their local station.
And apparently english sounds the best in songs because of the mixture of "hard" sounds from its german origins and the "soft" sounds from its french origins, which sounds better than those two sung on their own.