Beyonce's chores isn't iconic because its difficult. Its the exact opposite. She just jams to the music and lets it come naturally. It's less contrived and forced. People love that.
Britney isn't really a dancer, she's always been stiff as fvck. Rihanna is ugly and as result dances ugly. And Gaga.... well she tries.

The only one who can pull off actual difficult dancer caliber choreo is Cedrick.