3^3 is the way you write 3³ when you don't have any way to write the ³ .
Whichever way you write it, it means " 3 · 3 · 3 " . That's 27 .
I don't know what would be considered "simplifying" it. Maybe " 3³ "is a little simpler, but you can't always write that if your computer or your word processor doesn't give you a way to write exponents.
" 3 · 3 · 3 " certainly is not any simpler than " 3^3 ", so that's not it.
" 27 " may be simpler.