We love the Oxford comma. It brings clarity to sentences, it is aesthetically pleasing, and it copies speech.
Like all punctuation marks, it serves a purpose. The full stop brings a thought to a halt. The exclamation mark signals urgency. The comma represents a pause.
When we talk about a list, we use a comma to pause between items. I went shopping and bought a banana (pause), apple (pause), orange (pause), and three potatoes (full stop). We can understand immediately what has been purchased. This is so much easier on the ear than, for example Ratty, in Wind in the Willows, and his rapidfire list of what is in the picnic basket.
Clarity is essential to helping us understand. We are sure that Nelson Mandela was neither an 800-year-old demigod or dildo collector. This is, however, what the sentence says. Put the Oxford comma in, and we can see immediately that Peter Ustinov met with three distinct peopleThe Oxford Comma is essential. It is worth protecting at all costs.