Political correctness does not polarise ideas by suppressing them.
Political correctness makes people reconsider whether they are saying something of prejudicial or inappropriate.
Political correctness raises awareness about the severity of extreme opinions/toxic views that target minority groups.
Political correctness makes people consider that harmful views can lead to more drastic measures down the line.
For example, Anti-semitism first showed up as jokes and alienation before it lead to millions of Jews being murdered.