The proof is all of YouTube.
Katy needs bombastic production because her vocals aren't there, her songs don't require much vocals like a Whitney/Mariah/Celine concert. Who goes to a concert to hear a Katy vocal?

So, of course, the requirement of props wouldn't be as high for a REAL vocalist.
There are plenty of Whitney, Mariah and Celine's concerts and performances that had props and dancers. They aren't only balladeers.