Which of the following is not true about satire?

Satires often try to persuade the reader to do or believe something by showing the opposite view as absurd, or even vicious.

Some writers use a humorous tone in their satire, while others use a serious tone.

It often ridicules an aspect of society in hopes of bringing about social reform.
Satire is often written in a humorous way to be funny just for the sake of being funny.