Why Don't A Lot Of British/American Bands Sing And Dance?

Here in Korea, pretty much 99% of the Kpop idols dance. c:
Here's some talented idols who can sing and dance at the same time!
[youtube=https://youtu.be/JrdjYcNLOTA]
[youtube=https://www.youtube.com/watch?v=Il67eRft2jA]
[youtube=https://www.youtube.com/watch?v=4y9aLycW8Go]
[youtube=https://www.youtube.com/watch?v=4XyPdnTz_Q0][youtube=https://www.youtube.com/watch?v=Zc47fWI1mDI]
[youtube=https://www.youtube.com/watch?v=d2LmYat0T2w]
[youtube=https://www.youtube.com/watch?v=Y9ZTKmzp7Ew]
[youtube=https://www.youtube.com/watch?v=32xlppvyWC8]