Some years ago I went on an editing binge on Wikipedia, finding a bunch of templates that "misused" the phrase "due to" and changed them to "because of". As we all know, you must get this right:
"The flight delay was due to bad weather."
vs.
"The flight was delayed because of bad weather."
but never:
"The flight was delayed due to bad weather."
The next day, someone reverted all my changes and asked, "Mike, have you looked at a dictionary lately?"
Oops.
In that moment I was enlightened: I realized I could care less.
I even leave out the Oxford comma as often as I use it. In fact I leave out a lot of commas I used to put in.
But there is one case where the Oxford comma is still necessary. If you leave it out of this joke it ruins it:
"There are two hard problems in computer science: naming things, cache expiration, and off by one errors."