Political correctness is a framework of how to “act” (big key word there) or what can be said or what can’t be said and what is safe and won’t offend anyone.
But by stiffling actors so nobody can be offended by anything they could possiblg do i.e. the script is made safe for political corectfulness. The actors look like cardboard wooden and rubbish.
They are actually capable of much more but the material and the framework within which they are confined and boundaries that can not be crossed. The performances are bland and stiffled.
Yet the example you used was Natalie Portman in the PT, where she is wooden not because of political correctness (how fucking ridiculous an idea is it that pc makes actors wooden, not to mention the PT isn’t exactly politically correct), but because George Lucas wrote a script with shit dialogue and didn’t direct his actors well.