I don't understand the structure of the sentence. How does "far more polarizing" function here?

Native speaker’s answer
Rebecca
"Far more polarizing" functions as a comparative, saying that same-sex or co-ed education is a much more divisive argument than public or private schooling. In terms of structure, you could also say that they omit "what is" at the beginning of the sentence. Ex: I don't like going on rollercoasters. But what's far more terrifying is skydiving. Ex: Far cuter than puppies is kittens!