Oxford comma, is it necessary?

What would be an example sentence in which using the Oxford comma makes the meaning of the sentence less clear?

>the Oxford comma isn’t grammatically correct

Sure it is, it just does not agree with some style guides, but that is prescription for you. Outside of academia and journalism the Oxford comma is best used as needed, it can often clear up ambiguity, make things more clear/easier to read, and maintain structure.

>this, that, and one and two

>this, that, and, one and two

The argument can be made that sentence structure should be altered to avoid such situations and that would be wise if the style guide you are required to follow says to avoid the Oxford comma, but if you are writing for more literary purposes or just are not required to follow a style guide than using as needed opens up some possibilities.

I got in trouble for not using the much hated Oxford comma :(